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MedicineToday 2014; 15(6): 35-47

PEER REVIEWED FEATURE 2 CPD POINTS Therapies for common cutaneous fungal

KENG-EE THAI MB BS(Hons), BMedSci(Hons), FACD Key points A practical approach to the diagnosis and treatment of common fungal • Fungal should infections of the and is provided. Topical therapies always be in the differential are effective and usually used as first-line therapy, with oral diagnosis of any scaly . being saved for recalcitrant infections. Treatment should be for several • Topical antifungal agents are typically adequate treatment weeks at least. for simple tinea. • Oral antifungal therapy may inea and infections are among the dermatophytoses (tinea) and yeast infections be required for extensive most common diagnoses found in general and their differential diagnoses and treatments disease, fungal and practice and . Although are then discussed (Table). tinea involving the face, hair- antifungal therapies are effective in these bearing areas, palms and T infections, an accurate diagnosis is required to ANTIFUNGAL THERAPIES soles. avoid misuse of these or other topical agents. Topical antifungal preparations are the most • Tinea should be suspected if Furthermore, subsequent active prevention is commonly prescribed agents for dermatomy- there is unilateral just as important as the initial treatment of the coses, with systemic agents being used for and rash on both fungal infection. ­complex, widespread tinea or when topical agents feet – ‘one hand and two feet’ This article provides a practical approach fail for tinea or yeast infections. The pharmacol- involvement. to antifungal therapy for common fungal infec- ogy of the systemic agents is discussed first here. • Oral antifungal treatments tions of the skin and hair. It is not intended to can often be pulsed inter­mit­ be an in-depth treatise on derma­tomycoses, Systemic antifungal agents tently, reducing the overall and and cutaneous dose required. are not covered in detail. The initial section Terbinafine is a highly effective antifungal agent, briefly reviews the practical pharma­cology of by virtue of its fungicidal property. It is an ally- commonly used antifungal agents, in order to lamine and works by inhibiting squalene epoxi- guide their use. The defining features of various dase. It has greater affinity for fungal squalene

Dr Thai is a Consultant Dermatologist and Visiting Medical Officer at the Epicutaneous Patch Testing Clinic and Hair Copyright _Layoutand 1 Nail17/01/12 Clinic, Prince 1:43 PM of Wales Page Hospital, 4 Randwick; a Visiting Medical Officer at the Macquarie University Hospital,

© GETTY IMAGES/SPL CREATIVE Macquarie Park; and in private practice in Gordon, Sydney, NSW.

MedicineToday x JUNE 2014, VOLUME 15, NUMBER 6 35 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. Treating common fungal infections CONTINUED

epoxidase than the human type. Inhibition interactions and there are no contraindi- may reduce absorption of ; they results in a deficiency of ergosterol (an impor- cations to its use with other drugs. How- should be taken two hours after the anti- tant fungal cell wall constituent) and the ever, because it is an inhibitor of cytochrome fungal agent. Griseofulvin can increase the accumulation of squalene, both of which P450 2D6, care should be taken when metabolism of warfarin and the contra- disrupt fungal cell membranes. It is especially administering it to patients taking tricyclic ceptive pill. When co-administered with effective against infections caused by der- antidepressants and other drugs metabo- alcohol, patients should be warned about matophytes (, Micro- lised by this isozyme. the disulfiram-like reaction that can occur. sporum and ). About 80% of an oral dose of terbinafine Griseofulvin is absorbed, regardless of food intake, but Griseofulvin was the first important oral Itraconazole, a , is useful in the first-pass metabolism limits bioavailability antifungal agent available for the treat- treatment of onychomycosis and dermato­ to 40%. Terbinafine is lipophilic and thus ment of fungal skin infections. Histori- mycoses. It is also useful for infections widely distributed, with significant and cally its main use was in the treatment of caused by , and some rapid distribution in skin stratum cor- . Being only fungistatic, it nondermatophyte moulds. It acts by inhib- neum, sebum, hair and nails. is not as effective as the other agents iting 14α-demethylase, resulting in inhi- High concentrations of the described here. bition of ergosterol production from are reached in the within Treatment needs to be continuous until lanosterol. hours of commencement of therapy. After mycological and clinical cure when gri- Being a highly lipophilic drug, itracona- 12 days of terbinafine 250 mg per day, there seofulvin is used to treat zole is best taken with a meal. A low pH is enough drug in the skin to maintain a infections. This often leads to protracted gastric environment is also useful to aid minimum inhibitory concentration (MIC) courses (several weeks to months), espe- absorption. In patients who have relative for two to three weeks after cessation of cially with onychomycosis, for which up achlorhydria (i.e. those taking H2-antago- treatment. Terbinafine is found in the dis- to 18 months of treatment may be required. nists, proton pump inhibitors or antacids) tal after one week of therapy, and after It is important to note that griseofulvin or who are taking the drug on an empty six or more weeks of treatment it is detect- has no activity against the Candida stomach, absorption is aided by the able for at least another 30 weeks (indicat- and Malassezia (formerly known as ­co- ­administration of a cola soft drink. The ing the potential for continued action). It Pityrosporum). drug is often used in a pulsatile manner. is also found in the hair after one week of Typical doses in children are 10 to Itraconazole rapidly presents into the treatment, and may be detected for up to 15 mg/kg daily, with recalcitrant cases stratum corneum and persists for three to another 50 days after just two weeks of requiring up to 25 mg/kg daily, and in four weeks after cessation of therapy. In treatment. adults, 500 mg to 1 g daily. The medication the nail, a MIC is achieved after only one As terbinafine is metabolised in the liver is best taken with a fatty meal to increase week of 200 mg itraconazole twice a day. and the metabolites are excreted in the absorption. For children, the tablets can be After several one-week-per-month pulses urine, dose adjustment is required in crushed and administered with, for exam- of treatment, the drug can persist for patients with renal failure where the serum ple, chocolate, full-cream ice cream or months in the nail plate. Appreciable creatinine level exceeds 300 µmol/L. With peanut butter. The medication is presented amounts are present in hair after only one the exception of those with renal insuffi- to the skin via sweat, concentrating in the week of therapy, with higher concentrations ciency, dose adjustment is not required in stratum corneum. It is quickly cleared from found with longer pulses. Itraconazole can the elderly. skin and hair after cessation of therapy. persist for up to nine months after cessation Terbinafine is generally a very safe Although well tolerated, side effects are of therapy. agent. The most common adverse effects common with the use of griseofulvin and are headache, gastrointestinal symptoms include headaches, photosensitivity, drug and drug eruptions; hepatic and haema- , gastrointestinal , uri- Fluconazole is a commonly used tological complications are quite uncom- nary and menstrual disturbances, liver broad-spectrum triazole that, like other mon. Blood counts and liver function tests dysfunction and neurological effects azoles, inhibits 14α-demethylase. However, should be performed if terbinafine is to be (fatigue, mood changes, dizziness, blurred it is much less lipophilic and much less used continuously for more than six weeks. vision). Changes to spermatogenesis occur, protein-bound than other azoles. It has One peculiar side effect is a disturbance, and men taking griseofulvin should not very high bioavailability and its absorption or even loss, of taste in some patients, father children for at least six months after is not affected by food. which can be irreversible.Copyright _Layout 1 17/01/12ceasing 1:43 treatment.PM Page 4 When used as a once-a-week 150 mg

Terbinafine has no serious drug The use of antacids and H2-antagonists pulse, fluconazole is present in the skin

36 MedicineToday x JUNE 2014, VOLUME 15, NUMBER 6 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. TABLE. TREATMENT OPTIONS FOR COMMON CUTANEOUS FUNGAL INFECTIONS

Fungal infection First-line therapy Second-line therapy General notes

Tinea corporis, Topical terbinafine Oral terbinafine 250 mg for 2 to 4 Keep skin dry Tinea capitis, Topical weeks Identify and eliminate , Fluconazole 200 mg weekly for 2 to source , 4 weeks (off-label use) Itraconazole 200 mg twice daily for 1 week per month for several months Griseofulvin 500 mg daily for several weeks

Tinea incognito Oral agent as above, with topical agent as adjunct Cease topical use Identify and eliminate source

Tinea pedis – Topical terbinafine or – spray-on Add topical furoate Dry feet and interdigital type lotion lotion to reduce interdigital spaces Topical – tincture thoroughly, e.g. with hair dryer Tinea pedis – Topical terbinafine – cream Typically needs oral agent Add antifungal moccasin type Topical imidazoles Oral terbinafine 200 mg daily for 2 to powders to shoes 4 weeks Wear open shoes Fluconazole (off-label use) or whenever possible, itraconazole as above go barefoot at home Remove shoes under desk at work

Kerion Oral terbinafine 250 mg daily until clinically Fluconazole 200 mg weekly until Treat with oral agent and mycologically cured cured until clinically cured Antidandruff daily to reduce Itraconazole 200 mg twice daily for and start shedding of fungal elements 1 week per month regrowing Cephalexin 500 mg three times daily to treat Griseofulvin 500 mg daily until cured secondary bacterial infection Prednisone 0.25 to 0.5 mg/kg daily if significant inflammation or scarring

Seborrhoeic Scalp and body disease: daily antifungal Fluconazole 200 mg weekly for Daily scalp dermatitis shampoo for scalp and body for 10 days; 4 weeks shampooing to then twice weekly long-term. Treat top half of reduce accumulated body, down to groin; leave shampoo lather scale on for 10 minutes each time. Change type of Always use shampoo with each new bottle conditioner to restore Facial disease: topical imidazoles or topical moisture to hairs combination therapy such as 1% with either miconazole 2% or 1% creams

Pityriasis Econazole 1% as a foaming solution over Fluconazole 200 mg weekly for Discolouration takes versicolor 3 nights or antidandruff shampoo as for 4 weeks (off-label use) months to even out , followed by twice Itraconazole 200 mg once daily for Copyright _Layout 1 17/01/12 1:43 PM Page 4 weekly antifungal shampoo long-term 7 to 10 days

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after the first dose, and with continuous absorbs into and binds the stratum cor- mess. Tinctures are also useful in the therapy can persist several days after neum, sebum and hair follicles. High MICs webs, as they dry the area applied to by ­ cessation. It is present in the nail after one are achieved in the skin after a few days of virtue of the alcohol base (they are also dose as well, but after several months of therapy, and its avidity for the layer useful under the nail plate). Some commer- once-weekly therapy, it is still present in helps prevent reinfection during cial tinctures, however, can stain the the nail after six months. treatment. tissues. As the drug is primarily cleared by renal Creams and spray formulations of ter- Antifungal powders can be dusted into excretion, a dose adjustment is needed binafine are available. Creams are effective skin folds, helping dry the area. However, when there is renal impairment (creatinine on the body and can be used with little a powder used with any cream can result clearance, less than 50 mL/min). There is irritation in the folds. Spray preparations in a gritty paste, which causes irritation. no need for dose reduction in renally are useful in the interdigital areas, as the The author finds powders most useful impaired patients receiving a single dose sprayed lotion dries on the skin, avoiding when placed in shoes; they do not treat for vaginal candidiasis. maceration. Twice-daily applications are the tinea pedis per se, but can reduce the Fluconazole is very well tolerated. Head- most practical. rate of re-infection by reducing the fungal ache, gastrointestinal upset and mild liver Terbinafine is a well-tolerated topical load in the shoes and socks. function test abnormalities are uncommon. agent and should be considered a first-line Antifungal are useful in the At very high doses, anorexia and hair loss therapy for dermatophyte skin infections. treatment of seborrhoeic dermatitis. The have been reported. It is important to note that it is not effective two key clinical pearls of wisdom are to against Candida or Malassezia infections. leave the lathered preparation on for up to 10 minutes before rinsing to allow the anti- Oral ketoconazole was deregistered and Imidazoles fungal agents to work, and to regularly discontinued in Australia and New Zea- The topical antifungals are the rotate shampoos to reduce the risk of resist- land in December 2103 because of its risk most commonly prescribed antifungal ance to one active agent. In extensive tinea of hepatotoxicity. preparations. This group includes ketocona- capitis, antifungal shampoos are used with Before its discontinuation, oral keto- zole, , clotrimazole, econazole and a systemic agent in order to reduce the conazole was the oldest of the systemic miconazole. They are effective against most spread of fungal from the scalp. imidazoles available for the treatment of and against Candida and A foaming solution of econazole is use- fungal infections but had been largely Malassezia. Of interest, miconazole and ful in the initial treatment of replaced in clinical practice by terbinafine, econazole also show modest antibacterial versicolor or seborrhoeic dermatitis. griseofulvin, itraconazole and fluconazole. properties and may be serendipitously A two-part proprietary treatment kit It was, however, considered still useful in ­efficacious in treating , ecthyma is available for onychomycosis: a urea-­ the treatment of widespread pityriasis ver- and mild . containing ointment that is applied to the sicolor because of its significant excretion Practically, the various topical prep­ nail for one to three weeks to soften it, in eccrine sweat, a 10-day course being arations are equivalent in efficacy. They allowing most of it to be scraped away, generally regarded as being reasonably safe. should be used twice daily for dermato- and bifonazole cream that is then applied phyte infections, to increase efficacy and daily for four weeks. Topical antifungal agents to ensure that if forgotten occasionally, Imidazole preparations formulated with Topical antifungals are the most common patients are still getting therapy every day. hydrocortisone acetate (as are available for agents prescribed for dermatomycoses. In Clinicians should become familiar with a clotrimazole and miconazole) have the general, dermatophyte infections are better few products in different bases, i.e. creams, added benefit of the corticosteroid’s mild treated with terbinafine, and yeast infec- lotions, tinctures, powders and shampoos, anti-inflammatory effect. These are useful tions with the imidazoles. Regardless of allowing different agents to be used in where an inflammatory rash or accom- the treatment used, general measures that different­ situations. panies the infection, such as with sebor- keep infected areas dry and in good con- Topical imidazoles are often used to rhoeic dermatitis on the face and when dition are just as important. treat tinea pedis. The interdigital spaces there is irritancy and candidal co-infection are often moist with prolonged use of shoes in tinea of the skin folds. Terbinafine and socks. Thus, putting a cream prepara- Being both fungistatic and fungicidal, ter- tion here can perpetuate the maceration Amorolfine binafine is likely to be the most effective that occurs with tinea infections. Spray-on Amorolfine is a broad-spectrum topical topical antifungal therapy.Copyright As _Layout mentioned 1 17/01/12 lotions 1:43 are PM useful Page in 4 this site, as the product antifungal agent that also acts by disrupting earlier, it is highly lipophilic and efficiently can dry on the skin and not leave a boggy fungal cell membranes through inhibition

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treatment of infections that have a signif- based upon the body site infected, and this icant inflammatory component. The key is the classification followed in the discus- to avoiding misuse of a topical corticoster- sion below of common dermatophyte oid in fungal infections is an accurate diag- infections (tinea infections of the nail – nosis in the first instance. Tinea should tinea unguium, or onychomycosis – are always be considered in any eruption that common but beyond the scope of this arti- is scaly or has an annular or serpiginous cle). Two Malassezia infections are also appearance, and skin scrapings should be discussed. The treatments of these fungal taken for fungal microscopy and culture. infections are summarised in the Table. Once antifungal therapy has com- Figure 1. on a leg. Note menced, it is reasonable to occasionally add Body – tinea corporis the active, advancing border, central in a topical corticosteroid, tailoring the Tinea corporis, classically known as ‘ring- clearing and scale. Skin scrapings potency to the degree of inflammation, to worm’, presents as erythematous patches should be performed from the edges. reduce the inflammatory itch and discom- with scales on the trunk, arms or legs (Fig- fort. can also help restore ure 1). There should be an ‘active’ border the integrity of the skin and improve its with accentuation of the clinical findings; of ergosterol synthesis. It is available as an barrier function as the fungal infection is this is the spreading edge of the patch of over-the-counter lacquer paint formulation being treated. Practical examples include tinea. Patches may be quite large and exten- for the treatment of onychomycosis caused adding a corticosteroid lotion to an imida- sive with long-term infections, but the by dermatophytes and yeasts. Although zole lotion/spray in the treatment of inflam- classic features of scale and activity at the early clinical trials showed some benefit, it matory interdigital tinea, and using topical border should be present. Multiple patches is relatively expensive, has variable effec- or systemic corticosteroids in addition to may be found, and tinea in other body sites tiveness and is unlikely to be useful for antifungal therapy in the treatment of should be sought. extensive, deep onychomycosis; systemic highly inflammatory tinea capitis in chil- Tinea incognito. Patches of tinea inadvert- agents are best used for these infections. dren to reduce hair loss and scarring. ently treated with topical corticosteroids Patients are required to file down the will look less impressive, with less affected nail and apply the preparation on COMMON CLINICAL and little scale. This disguises the true a once- or twice-weekly basis until the DERMATOMYCOSES nature of the dermatophyte reaction, hence onychomycosis is cured. Most patients give Dermatomycoses are caused by dermato- the term ‘tinea incognito’. Rashes that are up with this treatment; of those who do phytes and some yeasts. The three classic spreading or poorly responsive to topical use it for more than a year, less than half sources of dermatophyte infections – or corticosteroids should prompt the consid- will achieve clinical cure. The role of amo- tinea – in humans are animals (zoophilic eration of corticosteroid-modified tinea. rolfine may well be only for white superfi- dermatophytes), the soil (geophilic derma- . Fungal folliculitis can cial onychomycosis. tophytes) and other humans (anthropo- occur in hair-bearing skin, manifesting as philic dermatophytes). These infections of follicular pustules in an area of tinea. It can Role of topical corticosteroids skin, hair and nails can present in a similar be accentuated by the use of topical Traditionally, the use of topical cortico­ fashion, although the zoophilic types tend corticosteroids. for treating cutaneous infections to be somewhat more inflammatory. It may has been discouraged. When potent topical be important to identify the source of the Differential diagnoses corticosteroids are used on dermatomy- in order to prevent further reinfec- The many differential diagnoses for the coses, the annular erythema of the rash tion or spread to others; for example, a new annular or discoid rash of tinea corporis can be reduced, making it look quite non- guinea pig, or other pocket may be include the following: specific. Thus the ‘ringworm’ loses its clas- the source of facial tinea in a young child • discoid eczema – the dry and scaly sic appearance – tinea incognito – and (through cuddling of the pet), and a child rash is rounded but not often annular misdiagnosis can result. Furthermore, with a may well disseminate the tinea (i.e. no central clearing); it can be topical corticosteroids can reduce the to classmates. intensely itchy, whereas tinea corporis body’s inflammatory/immune response to Fungal infections of the skin and hair may not be the infection and thus facilitate its spread. tend to be treated similarly regardless • – is typically a thicker The availability of several combination of the specific fungus causing the plaque than tinea corporis, with products, however, isCopyright testament _Layout to the 1 use 17/01/12- infection 1:43 PM. Page 4 thicker ­silvery scales, and not annular; fulness of corticosteroids in the adjuvant One common classification of tinea is it should be sought on the extensor

40 MedicineToday x JUNE 2014, VOLUME 15, NUMBER 6 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. Treatment Unless the clinician is absolutely certain of the diagnosis, skin scrapings from the edge of an annular rash should always be taken to diagnose tinea corporis. Microscopy should show fungal elements, and culture will identify the variant of fungus and sen- sitivities to aid treatment. A skin can be useful to rule out the more sinister differential diagnoses. Figure 2. Kerion of the scalp. As mentioned previously, identification Figure 3. Extensive inflammatory of the infection source is important to scarring and resultant hair loss around reduce reinfection. Tinea corporis in an a kerion of the scalp. surface of the elbows and knees individual may be due to autoinoculation • – is also ring-like, from another body site; tinea pedis, tinea Scalp – tinea capitis but occurs much more slowly and cruris and onychomycosis should be The clinical presentation of tinea capitis insidiously; there is never scale, as it sought. can vary greatly. Typically there is a patch is a deeper dermal eruption General measures such as fastidious of hair loss with easily extractable hairs but • fixed drug eruptions – tend to have a drying of skin folds is important. Treatment different of dermatophyte will cause peculiar pigmented, red or purple with topical terbinafine is generally more differing degrees of scaling and inflamma- appearance, and scale is not often a effective than with an imidazole. Treatment tion. The variants are: feature; new lesions occur with should occur twice daily for several weeks, • -type – discreet patch ­continued medication use, and older until the rash disappears completely. Any of hair loss with dull-grey hairs ones reactivate in the same spot other sources in a patient should be treated, coated with the fungal spores • subacute cutaneous erythema- and strategies for preventing reinfection ­(ectothrix infection) tosus – can present as an annular and may be needed (such as improving personal • black dot tinea – linear patches with polycyclic eruption that is scaly and hygiene, taking more care in public show- the hair shafts broken at skin level may have the appearance of an active ering facilities or having the family pet ( infection); there is border, thus looking very much like treated for fungal skin infections). ­minimal scale, although a low-grade tinea; however, it is found in a photo- Fungal folliculitis, extensive tinea cor- folliculitis is often seen distributed area, with worsening after poris, tinea incognito, kerion or any other • agminate folliculitis (diffuse pustular-­ solar exposure. Arthritis, facial rash atypical fungal infection should be treated type) – a sharply-defined dull red and other manifestations of cutaneous additionally with an oral antifungal agent. plaque studded with follicular pustules lupus should be sought Treatment should continue until clinical • kerion – a large, boggy, erosive, • annular planus – although cure is achieved. Oral terbinafine is highly ­pustular, inflammatory mass that typically occurring on the genitals, effective (250 mg daily for at least two to resembles an (Figure 2) this can inadvertently have an annular four weeks until the rash settles). It is not • – a rare variant that has a appearance on the body. The rash is on the Pharmaceutical Benefits Scheme for ­characteristic ‘cup-shaped’ scale at made up of small purple, raised this indication, but generics are available the base of the hair shaft. ­ with a characteristic lacy scale that make it a viable option. Fluconazole Scarring from excessive inflammation (Wickham’s striae) on the top of the 150 to 200 mg weekly for up to four weeks can lead to permanent hair loss (Figure 3). papules; itch is often a feature is therapeutic and economical (off-label • erythema annulare centrifugum – is use). Itraconazole 200 mg twice daily for one of several rare annular rashes that one week per month is an alternative, but Although it is important to recognise other represent a ‘reaction pattern’ to a variety the cost in Australia is prohibitive. Oral scalp disorders that can have scale and hair of stimuli; in most cases no cause is griseofulvin 500 mg daily is a traditional loss, differentiating tinea capitis is usually found. These lesions start as a small treatment, but less efficacious than other straightforward. Alopecia areata has no patch or that evolves slowly to agents. With any prolonged oral therapy, scale associated, nor does trichotilomania. a larger annular patch, with a liver function tests may be appropriate Seborrhoiec dermatitis should have no hair characteristic rimCopyright of scale _Layout that has 1 the 17/01/12 every 1:43 sixPM Pageweeks 4 or so to exclude loss. Psoriasis has thicker, adherent scale, free edge on the inner side of the ring. hepatotoxicity. and alopecia is not common. Other scarring

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adult men, tinea cruris can occur in teen- agers and women. Once again, there may be tinea at other sites, and the feet and nails should be checked. Scrapings for fungal microscopy and culture confirm the diagnosis. Note that chronic tinea corporis often involves skin folds and can be rather ­recalcitrant to therapy.

Figure 4. Candidiasis in the inguinal Figure 5. Submammary psoriasis. This Differential diagnosis region. Note the satellite lesions away can be difficult to differentiate from Infectious differential diagnoses for tinea from the main infection. tinea and seborrhoeic dermatitis. cruris are candidiasis and seborrhoeic dermatitis: • candidiasis – wet, macerated alopecias such as , recalcitrant cases (up to 1 g). erythematous folds with whitish lichen planopilaris and dissecting Should either terbinafine or griseofulvin discharge may be due to ­candidiasis, of the scalp are chronic conditions, each be contraindicated, the use of fluconazole which is characterised by the with a different quality of inflammation. (off-label use) or itraconazole is reasonable. presence of ‘satellite lesions’, red The doses would be as for tinea corporis papules or pustules further away Treatment but treatment should be continued until from the main front of the Skin scrapings and hair plucks should be clinical and mycological cure is achieved. erythematous rash (Figure 4). The sent for fungal microscopy and culture to The daily use of an antidandruff sham- submammary fold is a common site confirm the diagnosis and help guide poo is also useful to reduce the continued for candidiasis. It is important to therapy. shedding of spores from the patient’s scalp. remember that terbinafine is not As for other types of tinea, other body Furthermore, it may be important to keep effective in the treatment of sites of fungal infection should be sought a child away from school for the first two candidiasis and that the imidazole in an attempt to identify a source. Use of weeks of the infection, reducing the risk of antifungals work for both candidiasis an oral antifungal agent is mandatory spread to his or her schoolmates. and dermatophyte infections because of the involvement of hair follicles. Although kerion may resemble an • seborrhoeic dermatitis – can present Terbinafine is often the first choice, given abscess, incisional drainage is not useful in the flexures (the axillae and pubic at 250 mg daily for several weeks until clin- as there is no cavity, only inflammatory areas are common sites), although it ical and mycological cure is achieved. The granulation tissue. Often, however, there more often occurs in the scalp and author’s empirical habit is to review treat- is a coexistent bacterial infection. If this is eyebrows and on the face and chest. ment after six weeks, including a liver the case, an oral antifungal agent and a The rash is pale pink with friable, function test and looking for settling of the broad-spectrum such as loose small scales. inflammation and regrowth of hairs; fur- cephalexin should be used. Antifungal Noninfectious differential diagnoses ther therapy may be required. In children, therapy is prolonged, typically at least six for tinea cruris are flexural psoriasis and the daily dose of terbinafine is adjusted to weeks. Excessive inflammation may lead irritant : body weight: for children weighing up to to scarring alopecia; dermatologists may • flexural psoriasis – has no scale, 20 kg, use 62.5 mg (i.e. a quarter of a tablet); use oral corticosteroids in some cases to involves the depth of the fold and has for those weighing 20 to 40 kg, use 125 mg limit this inflammatory scarring. a characteristic glazed appearance; (half a tablet); and for those above 40 kg, the submammary and the inguinal use the full adult dose (250 mg; one Skin folds – tinea cruris folds are typical sites of involvement tablet). A typical site for flexural tinea is the ingui- (Figure 5) Griseofulvin is a traditional agent and nal fold. Tinea cruris is easily diagnosed • irritant contact dermatitis – dermatitis is now typically used as a second-line treat- and presents as a flexural erythematous secondary to urine in the folds can be ment for tinea capitis, at a dose of 500 mg/ rash with an active border; there may not seen in as napkin dermatitis day for adults and 10 mg/kg/day for children be a lot of scale, given the occluded nature and in the neglectful elderly as an for six weeks or longer.Copyright Higher _Layout doses 1may 17/01/12 of the 1:43 groin, PM Page but 4the rash is often itchy. ammoniacal dermatitis. This be required in children (15 mg/kg/day) or Although most commonly ascribed to ­eczematous rash typically spares

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Figure 7. Tinea incognito. Treatment of tinea faciei with topical corticosteroid Figure 8. Kerion of the moustache has obscured its classic features. area.

Figure 6. Tinea faciei. The source of the infection was a new kitten. help with the diagnosis. suspected, a history of possible Fungal folliculitis of the beard (tinea exposure needs to be explored barbae) may be quite inflammatory and • – typically affects the the depths of the folds, although can present as a kerion; hairs are easily convexities of the mid face (cheeks, not always. Co-infection with extracted (Figure 8). nose, chin). Flushing and blushing are Candida or the incidental presence of common historical features, and the a dermatophyte should always be Differential diagnosis rash is of telangiectasias, background considered. There are multiple differential diagnoses erythema, papules and pustules. There to be considered with a facial rash. A skin is no active border per se, and rosacea Treatment scraping should make the diagnosis of tinea often spares the nasolabial folds. Tinea cruris should be treated the same easier. Occasionally a biopsy can be per- Perioral dermatitis typically occurs way as tinea corporis, with deliberate dry- formed, though the clinician needs to con- around the peri-alar lip, and extends to ing of the folds being particularly impor- sider the legacy of a small . the skin around the rest of the tant. A change in underwear style that Differential diagnoses include the cutaneous lip and chin, including the avoids skin-on-skin contact in the depth following: nasolabial folds. Papules and pustules of the folds can help aerate the fold and • seborrhoeic dermatitis and facial accompany the rash. It is associated in reduce sweating (i.e. a style where there is ­psoriasis – as well as being difficult to many cases with the use of potent a layer of fabric on the as well as the distinguish from tinea faciei, these two topical corticosteroids on the face. genital area; boxer shorts may be too loose conditions can be difficult to • cutaneous lupus erythematosus – if and allow the fold to occlude so there is distinguish from each other. Both the rash is photosensitive, lupus skin against skin). have an erythematous rash with greasy, should be suspected as it can be quite loose scales but seborrhoeic dermatitis inflammatory, scaly, scarring and Face – tinea faciei, is typically found on the mid face, over annular. Rash should be sought in Tinea faciei often presents in an annular the eyebrows and paranasal sinuses other parts of the skin, especially the pattern similar to tinea corporis (Figure 6). (and as on the scalp) whereas photoexposed areas, and systemic However, topical corticosteroids are often psoriasis is found on the rest of the illness also. A biopsy is mandatory prescribed initially, leading to tinea incog- body and on the margins of the scalp if the patient does not respond to nito (Figure 7). Solar exposure can worsen • and contact antifungal therapy or if there is the inflammation. As mentioned earlier, dermatitis – atopic dermatitis is systemic illness. may be the source of facial tinea, and common on the face, with the eyelids the possibility that a new pet is the source affected most often in adults. The skin Treatment of fungus should be explored. Although tends to be drier than with tinea faciei, Therapy is as for tinea corporis; a systemic much less commonly recognised than with ill-defined edges to the rash. antifungal is likely to be required for tinea elsewhere, theCopyright clinical features _Layout of1 an17/01/12 Contact1:43 PM dermatitis Page 4 may look similar to extensive disease, folliculitis and beard annular rash with an active border should atopic eczema; if contact dermatitis is kerion.

44 MedicineToday x JUNE 2014, VOLUME 15, NUMBER 6 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. Figure 11. Moccasin tinea pedis. Note the dry scaly fissured infected skin involving the entire sole.

Figure 10. Interdigitial tinea pedis. Note should be at the edge of the erythema the white, boggy macerated skin in the for the greatest yield of hyphae depth of the fold, and the associated • inflammatory tinea – highly Figure 9. Tinea manuum. Note the inflammatory tinea pedis on the inflammatory tinea pedis can have scaly, serpiginous superior border just adjacent skin. vesicles, pustules, erosion and above the metacarpophalangeal maceration. joints. Diagnosis is made difficult due agent may be appropriate (see tinea corpo- to prior topical corticosteroid use. ris). Once again, treatment is until clinical Differential diagnosis cure, which can take several weeks. Differential diagnoses may include bacte- – tinea manuum rial cellulitis, pustular psoriasis and sec- Tinea of the hands can be difficult to diag- Feet – tinea pedis ondarily infected pompholyx. Once again, nose and is often confused with pompho- The feet are an exceedingly common site fungal scrapings for microscopy and cul- lyx, hand dermatitis, psoriasis and for dermatophyte infections. Spots of ring- ture are useful, but also bacterial swabs to keratolysis exfoliativa. A scaly rash that has worm on the dorsum of the feet are easy rule out a secondary or co-infection. an active border should be easily diagnosed to diagnose, but there are several variants In patients with recurrent cellulitis of as tinea (Figure 9). More often, the pres- that clinicians should recognise: the legs, it is important to look for and treat entation is a dry, slightly scaly and peeling • interdigital tinea (‘athlete’s foot’) – tinea pedis. The chronic dermatophyte erythema of the palmar surface that can often occurs in the setting of a wet, infection creates broken skin, which is the be confused with dermatitis. It can also be macerated webspace, which often has portal of entry for the responsible quite inflam­matory, with at the broken, boggy, white skin (Figure 10). for cellulitis. edge, like p­ ompholyx. The rash can affect This should be seen as an infected both the palmar and dorsal surface in ­irritant , where there is both Treatment continuity with each other. A classic an inflammatory irritant dermatitis as General measures are important to keep description is that only one hand is well as the dermatophyte infection. the feet as dry as possible. These measures involved; the above-mentioned differential The ringworm component of include: diagnoses are often symmetrical. inter­digital tinea may spread to the • fastidious drying of the feet and the Other areas of co-infection are possible, adjacent dorsum of the foot toe webs after showering – using a and the feet should always be checked as • moccasin tinea – describes an hair dryer on a low heat setting can often there is ‘one hand, two feet’ involved erythematous, scaly fungal infestation help with tinea. Onychomycosis can be seen on of the plantar surface of the feet, as if • wearing open shoes when possible, to the fingernails. the patient was wearing a pair of air the feet – if appropriate, desk-bound ‘fungal moccasins’ (Figure 11). office workers should remove their Treatment Moccasin tinea is common, and often shoes when seated to reduce sweating Skin scrapings, fungal microscopy and missed as many older patients have • regular changes of socks, and laundering culture is key to a diagnosis. Topical anti- dry scaly feet. An active margin at the at above 60°C to decontaminate them fungal agents can be used for small areas. sides of the feet, where the erythema of fungus However, given that tinea manuum can be and scale appear to stop, should be • use of antifungal powders in shoes – to extensive and commonlyCopyright coexist _Layout with other1 17/01/12 looked1:43 PM for. Page It may 4 coexist with help prevent reinfection in the future. areas of dermatophyte infection, an oral interdigital tinea. Skin scrapings With interdigital tinea, therapeutic

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The treatment rationale is that these areas are where the reservoir of yeast is greatest. Patients should wait for about 10 minutes before rinsing off the shampoo, to allow it time to work. Initial treatment with the shampoo is every day for seven to 10 days to eliminate the yeast. Subsequently, a long- term, twice-weekly, all-over body shampoo regimen limits further fungal overgrowth. Patients should buy a different shampoo Figure 12. Seborrhoeic dermatitis. Figure 13. Pityriasis versicolor. (with a different active ingredient) each time, thus preventing the development of antifun- gal resistance. Any flare of disease should lotions/sprays (e.g. terbinafine spray-on Differential diagnosis trigger a change in shampoo and another lotion, econazole spray-on lotion or Psoriasis is the most common differential seven to 10-day course of therapy. miconazole tincture) should be used as they diagnosis for seborrhoeic dermatitis. Pso- Recalcitrant cases can be treated with a dry on the skin, whereas cream-based prod- riasis, however, has a more chronic course, short course of oral antifungal agent. Various ucts may encourage more maceration and more intense erythema and a thicker layer regimens are available but a simple one wetness. If there is excessive inflammation, of scales. Rash should be looked for on more involves fluconazole 200 mg once a week for a topical antifungal can be used in con- pathognomonic sites, such as elbows, knees four weeks. The above anti­dandruff regimen junction with a topical corticosteroid lotion, and affected nails. Sometimes it is not pos- should then be used twice weekly as well. such as mometasone furoate 0.1% drops. sible to differentiate seborrhoeic dermatitis Moccasin tinea and tinea with inflam- and psoriasis, and the term sebopsoriasis Pityriasis versicolor matory changes can be recalcitrant to is used. Pityriasis versicolor is another yeast infec- topical therapy. Should regular use of tion caused by Malassezia. It manifests as ­terbinafine or an imidazole cream fail, then Treatment a salmon-pink spotty, scaly rash on fair a systemic antifungal agent should be As the putative cause of this rash is the over- skin, and as a paler or white spotty, scaly considered. growth of a commensal organism, treatment rash on darker or tanned skin (Figure 13). is aimed at reducing the skin’s yeast load as It is distributed mainly over the back, shoul- Seborrhoeic dermatitis well as targeting the inflammation. ders, trunk and upper limbs. The infection Seborrhoeic dermatitis is probably due to Facial dermatitis will usually respond to is most prevalent in the warmer months as an inflammatory response to Malassezia. a mild topical corticosteroid/imidazole the hot, humid, sweaty conditions favour This yeast is a commensal organism on ­combination such as hydrocortisone 1%/ fungal proliferation. but appears to overgrow in miconazole 2% cream or hydrocortisone some individuals, leading to an inflamma- 1%/clotrimazole 1% cream used two to three Differential diagnosis tory reaction. times daily. Alternatively, ketoconazole 2% Pityriasis versicolor may be confused with Seborrhoeic dermatitis presents as a pale cream can be used alone. For more severe guttate psoriasis. However, the rash of pink, ill-defined erythematous rash char- inflammation, a mid-potency cortico­ pityriasis versicolor is macular and the acterised by loose, flaky scale. Dandruff is can also be used, such as desonide 0.05% scales are powdery and fine, and that of seborrhoeic dermatitis on the scalp. The lotion. guttate psoriasis consists of small plaques mid face, along the eyebrows, nasolabial To treat scalp and skin disease as well as with thicker scales. folds, and cheeks and beard areas are clas- reduce the overall yeast load, an antidandruff sically affected. The rash may also be pres- shampoo is used. olamine solu- Treatment ent on the central chest, upper back and in tion has the greatest in vitro fungicidal activ- Topical antifungals are effective for pityri- the axillae (Figure 12). Seborrhoeic derma- ity, but in practice all antifungal shampoos asis versicolor, but need to be used over a titis is more common in people who are are equally effective. Patients are advised to large area. Econazole is available as a 1% psychologically stressed, fatigued or in poor wet the scalp and entire skin, and then turn foaming solution specifically for this pur- general health. HIV infection and other the shower off. The shampoo is used to lather pose. This is distributed on wet skin after are a common asso- up the scalp hair and as a bodywash to cover an evening shower and left on overnight; ciation, as are Parkinson’sCopyright disease, _Layout stroke 1 17/01/12 the 1:43top half PM of Page the body,4 including the face, the top half of the body is treated, including and other neurological diseases. beard, chest, back, axillae and pubic region. the scalp. Thereafter, a twice-weekly FIGURE 13: © GETTY IMAGES/ SPL CREATIVE

46 MedicineToday x JUNE 2014, VOLUME 15, NUMBER 6 Downloaded for personal use only. No other uses permitted without permission. © MedicineToday 2014. antidandruff shampoo regimen is instituted to reduce the rate of relapse (as for seborrhoeic dermatitis, see above). Alternatively, recalcitrant cases can be treated with fluconazole (off-label use) or itraconazole. The characteristic scaling of pityriasis versicolor is a good indication of continued activity, as it disappears with effective fungal clearance. The pink spots disappear over a few weeks, but repigmentation may take months. Patients are advised that should they subject themselves to a suntan within the next few months, the previously affected spots can look very obviously pale. When the next summer does come, patients can use the twice-weekly antidandruff shampoo regimen to reduce the risk of the yeast repopulating their skin.

CONCLUSION The key to the effective use of antifungal agents is an initial accurate diagnosis of the fungal infection. The classic finding of the active border and fine scale is pathognomonic of tinea, and dermatophyte infection should always be in the differential diagnosis when dealing with red, scaly rashes. Topical antifungal preparations are usually adequate treatment for simple tinea but systemic antifungal treatment should be considered with complex, widespread tinea or when topical agents fail. A relatively dry skin is an important general treatment measure. MT FURTHER READING

Mycology Online. University of Adelaide. http://mycology.adelaide.edu.au/ Mycoses/Cutaneous/Dermatophytosis (accessed May 2014).

UpToDate. Dermatophyte infections. http://uptodate.com/contents/­ dermatophyte-tinea-infections (accessed May 2014).

DermnetNZ. http://dermnetnz.org/fungal/tinea.html (accessed May 2014).

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