Karl T. Clebak, MD, FAAFP; Leesha Helm, MD, MPH; Matthew F. The many variants of Helm, MD; Elizabeth V. Seiverling, MD Penn State College of Erythema, skin thickening, and scales typify most cases, ­Medicine, Department of Family­ and Community­ but other patterns exist. Tx choices may differ, depending ­Medicine, Hershey (Drs. Clebak and L. Helm); on how much body surface area is covered. Penn State College­ of Medicine, Department­ of ­Dermatology (Dr. M. Helm); Maine Medical Center, he “heartbreak of psoriasis,” coined by an advertiser in Department of PRACTICE ­Dermatology, Portland (Dr. the 1960s, conveyed the notion that this disease was a Seiverling). RECOMMENDATIONS cosmetic disorder mainly limited to skin involvement. ❯ Consider if T John Updike’s article in the September 1985 issue of The New kclebak@ small (often < 1 cm) pink scaly Yorker, “At War With My Skin,” detailed Mr. Updike’s feelings of pennstatehealth.psu.edu papules appear suddenly, isolation and stress related to his condition, helping to reframe The authors reported no particularly in a child who 1 potential conflict of interest has an upper respiratory the popular concept of psoriasis. Updike’s eloquent account relevant to this article. tract infection. C describing his struggles to find effective treatment increased public awareness about psoriasis, which in fact affects other ❯ Document extent of disease body systems as well. using a tool such as the Psoriasis Area and Severity The overall prevalence of psoriasis is 1.5% to 3.1% in the 2,3 Index, which calculates United States and United Kingdom. More than 6.5 million 3 a score based on the area adults in the United States > 20 years of age are affected. The (extent) of involvement most commonly affected demographic group is non-­Hispanic surrounding 4 major Caucasians. anatomical regions. C ❯ Consider prescribing UV light treatment or a Our expanding knowledge combination of alcitretin and of pathogenesis topical corticosteroid if Studies of genetic linkage have identified genes and single > 10% of the body surface area nucleotide polymorphisms associated with psoriasis.4 The is involved but joints are not interaction between environmental triggers and the innate affected. C and adaptive immune systems leads to keratinocyte hyperp- Strength of recommendation (SOR) roliferation. Tumor necrosis factor (TNF), interleukin (IL) 23, A Good-quality patient-oriented and IL-17 are important cytokines associated with psoriatic evidence inflammation.4 There are common pathways of inflammation B Inconsistent or limited-quality patient-oriented evidence in both psoriasis and cardiovascular disease resulting in oxida- 4  C Consensus, usual practice, tive stress and endothelial cell dysfunction. Ninety percent of opinion, disease-oriented evidence, case series early-onset psoriasis is associated with human leukocyte anti- gen (HLA)-Cw6.4 And alterations in the microbiome of the skin may contribute, as reduced microbial diversity has been found in psoriatic lesions.5

Comorbidities are common Psoriasis is an independent risk factor for diabetes and major adverse cardiovascular events.6 Hypertension, dyslipidemia, inflammatory bowel disease, nonalcoholic fatty liver disease, chronic kidney disease, and lymphoma (particularly cutane-

192 THE JOURNAL OF FAMILY PRACTICE | MAY 2020 | VOL 69, NO 4 ous T-cell lymphoma) are also associated FIGURE 1 with psoriasis.6 is frequent- Psoriasis appearing ly encountered with cutaneous psoriasis; however, it is often not recognized until late on traumatized tissue PHOTOS COURTESY OF JEFFREY J. MILLER, MD, MBA, PENN STATE COLLEGE OF MEDICINE, AND BRYAN E. ANDERSON, MD, PENN in the disease course. There also appears to be an associa- tion among psoriasis, dietary factors, and celiac disease.7-9 Positive testing for IgA anti-endomysial antibodies and IgA tissue transglutaminase antibodies should prompt consideration of starting a gluten-free diet, which has been shown to improve psoriatic lesions.9 In addition to its impact on physi- cal health, cutaneous psoriasis often affects mental health. Increased anxiety, depres-

sion, and sleep disorders are commonly en- STATE COLLEGE OF MEDICINE, DEPARTMENT OF DERMATOLOGY, PA countered, revealing the far-reaching effects of psoriasis. The persistent associated itch of psoriasis is often distressing and negatively impacts the patient’s quality of life.

The different types of psoriasis The classic presentation of psoriasis involves stubborn plaques with silvery scale on exten- sor surfaces such as the elbows and knees. The severity of the disease corresponds with the amount of body surface area affected. While plaque-type psoriasis is the most com- mon form, other patterns exist. Individuals Koebner phenomenon refers to psoriatic lesions that may exhibit 1 dominant pattern or multiple may occur in an area of trauma. Lesions may also have psoriatic variants simultaneously. Most types a linear streak-like appearance (around shirt and leg of psoriasis have 3 characteristic features: er- of tattoo). ythema, skin thickening, and scales. Certain history and physical clues can ❚ Guttate psoriasis (FIGURE 3) features aid in diagnosing psoriasis; these include the small (often < 1 cm) pink scaly papules that Koebner phenomenon, the Auspitz sign, and appear suddenly. It is more commonly seen the Woronoff ring. The Koebner phenomenon in children and is usually preceded by an refers to the development of psoriatic lesions upper respiratory tract infection, often with in an area of trauma (FIGURE 1), frequently re- Streptococcus.10 If strep testing is positive, sulting in a linear streak-like appearance. The guttate psoriasis may improve after appropri- Auspitz sign describes the pinpoint bleeding ate antibiotic treatment. that may be encountered with the removal of ❚ Erythrodermic psoriasis (FIGURES 4A a psoriatic plaque. The Woronoff ring is a pale and 4B) involves at least 75% of the body with blanching ring that may surround a psoriatic erythema and scaling.11 can lesion. be caused by many other conditions such as ❚ Chronic plaque-type psoriasis atopic dermatitis, a drug reaction, Sezary syn- (FIGURES 2A and 2B), the most common vari- drome, seborrheic dermatitis, and ant, is characterized by sharply demarcated rubra pilaris. Treatments for other conditions pink papules and plaques with a silvery scale in the differential diagnosis can potentially in a symmetric distribution on the extensor make psoriasis worse. Unfortunately, find- surfaces, scalp, trunk, and lumbosacral areas. ings on a skin biopsy are often nonspecific,

MDEDGE.COM/FAMILYMEDICINE VOL 69, NO 4 | MAY 2020 | THE JOURNAL OF FAMILY PRACTICE 193 FIGURE 2 Plaque psoriasis A B

Sharply demarcated pink plaques with silvery scales are commonly seen on the extensor surfaces (A), the scalp (B), trunk, and lumbosacral area.

FIGURE 3 FIGURE 4 Guttate psoriasis Erythrodermic psoriasis A

The small, pink scaly papules of guttate psoriasis appear suddenly, and usually in children who have an B upper respiratory tract infection.

making careful clinical observation crucial to arriving at an accurate diagnosis. ❚ Pustular psoriasis is characterized by bright erythema and sterile pustules. Pustu- lar psoriasis can be triggered by pregnancy, sudden tapering of corticosteroids, hypo- calcemia, and infection. Involvement of the palms and soles with severe desquamation can drastically impact daily functioning and quality of life. ❚ Inverse or flexural psoriasis (FIGURES 5A and 5B) is characterized by shiny, pink-to-red sharply demarcated plaques involving inter- triginous areas, typically the groin, inguinal crease, axilla, inframammary regions, and This form of psoriasis involves at least 75% of the body with erythema and scaling, and can be difficult intergluteal cleft. to differentiate from such conditions as atopic or ❚ Geographic tongue describes psoria- seborrheic dermatitis and .

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FIGURE 5 FIGURE 6 Nail psoriasis A

B

Nail psoriasis is often quite distressing for patients and can be difficult to treat. Pitting of the nails with psoriasis. Onycholysis and subungual hyperkeratosis may also occur.

tous scaling lesions or involve thickening and scale without associated erythema. ❚ Psoriatic arthritis can cause significant joint damage and disability. Most affected

Shiny, pink-to-red sharply demarcated plaques individuals with psoriatic arthritis have a involve intertriginous areas such as the groin (A) and history of preceding skin disease.12 There are intergluteal cleft (B). no specific lab tests for psoriasis; radiologic studies can show bulky syndesmophytes, sis of the tongue. The mucosa of the tongue central and marginal erosions, and periosti- has white plaques with a geographic border. tis. Patterns of joint involvement are variable. Instead of scale, the moisture on the tongue Psoriatic arthritis is more likely to affect the causes areas of hyperkeratosis that appear distal interphalangeal joints than rheumatoid white. arthritis and is more likely to affect the meta- ❚ Nail psoriasis can manifest as nail pit- carpophalangeal joints than osteoarthritis.13 ting (FIGURE 6), oil staining, onycholysis (distal Psoriatic arthritis often progresses insid- lifting of the nail), and subungual hyperkerato- iously and is commonly described as causing sis. Nail psoriasis is often quite distressing for discomfort rather than acute pain. Enthesitis, patients and can be difficult to treat. inflammation at the site where tendons or lig- ❚ Palmoplantar psoriasis (FIGURES 7A aments insert into the bone, is often present. and 7B) can be painful due to the involvement Joint destruction may lead to the telescoping of the palms of the hands and soles of the feet. “opera glass” digit (FIGURE 8). Lesions will either be similar to other psori- ❚ Drug-provoked psoriasis is divided atic plaques with well-demarcated erythema- into 2 groups: drug-induced and drug-­

MDEDGE.COM/FAMILYMEDICINE VOL 69, NO 4 | MAY 2020 | THE JOURNAL OF FAMILY PRACTICE 195 FIGURE 7 Palmoplantar psoriasis A B

Palms of the hands (A) or soles of the feet (B) exhibit psoriatic plaques with well-demarcated erythematous scaling lesions. Palmoplantar psoriasis can also involve thickening and scale without associated erythema (not shown).

FIGURE 8 and antimalarials.10 Other potentially aggra- Psoriatic joint damage of hand vating agents include antibiotics, digoxin, and nonsteroidal anti-inflammatory drugs.10

Consider these skin disorders in the differential diagnosis The diagnosis of psoriasis is usually clinical, and a skin biopsy is rarely needed. However, a range of other skin disorders should be kept in mind when considering the differential di- agnosis. ❚ Mycosis fungoides is a type of cutane- ous T-cell lymphoma that forms erythema- tous plaques that may show wrinkling and epidermal atrophy in sun-protected sites. Pictured here is arthritis mutilans of the hand. Note the shortening of the digits due to bony destruction. The resulting excess skin Onset usually occurs among the elderly. becomes folded and retracted in an appearance similar to ❚ Pityriasis rubra pilaris is characterized telescoping “opera glasses.” by salmon-colored patches that may have small areas of normal skin (“islands of spar- aggravated. Drug-induced psoriasis will im- ing”), hyperkeratotic follicular papules, and prove after discontinuation of the causative hyperkeratosis of the palms and soles. drug and tends to occur in patients without a ❚ Seborrheic dermatitis, dandruff of the personal or family history of psoriasis. Drug- skin, usually involves the scalp and nasola- aggravated psoriasis continues to progress af- bial areas and the T-zone of the face. ter the discontinuation of the offending drug ❚ usually appears slightly and is more often seen in patients with a his- more purple than psoriasis and typically in- tory of psoriasis.14 Drugs that most commonly volves the mouth, flexural surfaces of the provoke psoriasis are beta-blockers, lithium, wrists, genitals, and ankles.

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❚ Other conditions in the differential in- (TCS), vitamin D analogs, topical calcineu- clude chronica, which rin inhibitors, and vitamin A creams. Recal- may be identified on skin biopsy. Inverse pso- citrant disease will likely require ultraviolet riasis can be difficult to differentiate from can- (UV) light treatment or a systemic agent.15 dida , erythrasma, or . ❚ If > 10% of the body surface area is A potassium hydroxide (KOH) prepa- involved, but joints are not involved, con- ration can help differentiate psoriasis from sider UV light treatment or a combination of candida or tinea. In psoriasis, a KOH test will alcitretin and TCS. If the joints are involved, be negative for fungal elements. Mycology likely initial options would be methotrexate, culture on skin scrapings may be performed cyclosporine, or TNF-α inhibitor. Additional to rule out fungal infection. Erythrasma may options to consider are anti-IL-17 or anti- exhibit a coral red appearance under Wood IL-23 agents.15 lamp examination. ❚ If there’s joint involvement. In indi- If a lesion fails to respond to appropriate viduals with mild peripheral arthritis involv- treatment, a careful drug history and biopsy ing fewer than 4 joints without evidence of can help clarify the diagnosis. joint damage on imaging, nonsteroidal anti- inflammatory drugs are the mainstay of treat- ment. If the peripheral arthritis persists, or if Document disease it is associated with moderate-to-severe ero- It’s important to thoroughly document the sions or with substantial functional limita- While plaque- extent and severity of the psoriasis and to tions, initiate treatment with a conventional type psoriasis monitor the impact of treatment. The Pso- disease-modifying antirheumatic drug. If is the most riasis Area and Severity Index is a commonly the disease remains active, consider biologic common form, used method that calculates a score based on agents. other patterns the area (extent) of involvement surround- exist and may ing 4 major anatomical regions (head, upper even occur extremities, trunk, and lower extremities), as Case studies simultaneously. well as the degree of erythema, induration, Mild-to-moderate psoriasis and scaling of lesions. The average redness, Patient A is a 19-year-old woman presenting thickness, and scaling are graded on a scale of for evaluation of a persistently dry, flaking 0 to 4 and the extent of involvement is calcu- scalp. She has had the itchy scalp for years, lated to form a total numerical score ranging as well as several small “patches” across her from 0 (no disease) to 72 (maximal disease). elbows, legs, knees, and abdomen. Over- the-counter emollients have not helped. The patient also says she has had brittle nails on Many options several of her fingers, which she keeps cov- in the treatment arsenal ered with thick polish. Many treatments can improve psoriasis.9,15-19 The condition exemplified by Patient Most affected individuals discover that emol- A can typically be managed with topical lients and exposure to natural sunlight can be products. effective, as are soothing baths (balneothera- ❚ Topical steroids may be classified by py) or topical coal tar application. More per- different delivery vehicles, active ingredi- sistent disease requires prescription therapy. ents, and potencies. The National Psoriasis Individualize therapy according to the sever- Foundation's Topical Steroids Potency Chart ity of disease, location of the lesions, involve- can provide guidance (visit www.psoriasis. ment of joints, and comorbidities (FIGURE 9).15 org/about-psoriasis/treatments/topicals/ ❚ If ≤ 10% of the body surface area is steroids/potency-chart and scroll down). involved, treatment options generally are ex- Prescribing an appropriate amount is im- plored in a stepwise progression from safest portant; the standard 30-g prescription tube and most affordable to more involved thera- is generally required to cover the entire skin pies as needed: moisturization and avoidance surface. Ointments have a greasy consistency of repetitive trauma, topical corticosteroids (typically a petroleum base), which enhances

MDEDGE.COM/FAMILYMEDICINE VOL 69, NO 4 | MAY 2020 | THE JOURNAL OF FAMILY PRACTICE 197 FIGURE 9 Treatment for localized psoriasis without joint involvement15

Face or Scalp Palmoplantar Guttate Nail intertriginous areas

High-potency TCS Low-to-medium High-potency TCS Tar shampoo or TCS Rule out strep under occlusion, or potency TCS (cream and/or keratolytic (solution, foam, or TCS-impregnated or ointment) + steroid shampoo) tape steroid-sparing agent (TCI or vitamin D analog) Medium-potency Acitrentin or Biologic agent TCS methotrexate

Biologic agent UV light

TCI, topical calcineurin inhibitor; TCS, topical corticosteroid; UV, ultraviolet.

potency and hydrates the skin. Creams and log in combination with a high-potency lotions are easier to rub on and spread. Gels TCS, systemic treatment, or phototherapy are alcohol based and readily absorbed.16 So- can provide greater efficacy, a more rapid lutions, foams, and shampoos are particular- onset of action, and less irritation than can ly useful to treat psoriasis in hairy areas such the vitamin D analog used alone.21 If used as the scalp. in combination with UV light, apply topical Corticosteroid potency ranges from vitamin D after the light therapy to prevent Class I to Class VII, with the former being the degradation. most potent. While TCS products are typically ❚ UV light therapy is often used in ­cases effective with minimal systemic absorption, it refractory to topical therapy. Patients are is important to counsel patients on the risk of typically prescribed 2 to 3 treatments per skin atrophy, impaired wound healing, and week with narrowband UVB (311-313 nm), skin pigmentation changes with chronic use. the excimer laser (308 nm), or, less com- With nail psoriasis, a potent topical steroid monly, PUVA (UV treatment with psoralens). (including flurandrenolide [Cordran] tape) Treatment begins with a minimal erythema applied to the proximal nail fold has shown dose—the lowest dose to achieve minimal benefit.20 erythema of the skin before burning. When ❚ Topical calcineurin inhibitors (TCIs; that is determined, exposure is increased as eg, tacrolimus ointment and pimecrolimus needed—depending on the response. If this cream) are anti-inflammatory agents often is impractical or too time-consuming for used in conjunction with topical steroids to the patient, an alternative recommendation minimize steroid use and associated adverse would be increased exposure to natural sun- effects.15 A possible steroid-sparing regimen light or even use of a tanning booth. However, includes using a TCI Monday through Friday patients must then be cautioned about the in- and a topical steroid on the weekend. creased risk of skin cancer. ❚ Topical vitamin D analogs (calcipot- riene, calcipotriol, calcitriol) inhibit pro- Refractory/severe psoriasis liferation of keratinocytes and decrease Patient B is a 35-year-old man with a long- the production of inflammatory media- standing history of psoriasis affecting his scalp tors.15,17-19,21 Application of a vitamin D ana- and nails. Over the past 10 years, psoriatic le-

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TABLE Biologic agents for treating psoriasis22

Agent (brand name; Maintenance Baseline lab work Pertinent patient Adverse effects Approved uses mechanism of action) dosing schedule (maintenance) history Rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Adalimumab juvenile idiopathic (­Humira; TNF-α SQ q2 wk arthritis, Crohn inhibitor) disease, ulcerative colitis, plaque psoriasis, hidradenitis suppurativa, uveitis Ask about Risk of URI, prior/current Psoriatic arthritis, Golimumab (­Simponi; rheumatoid arthritis, SQ q8 wk HBV, HCV, PPD/ injection site ­malignancy, CHF, TNF-α inhibitor) ankylosing spondylitis, interferon gamma reaction, immunosuppression, ulcerative colitis release assay, CBC, reactivation of hypersensitivity CMP; also consider TB, psoriatic reactions, Rheumatoid arthritis, HIV test in high- reaction current/frequent plaque psoriasis, infections, family psoriatic arthritis, Etanercept (Enbrel; risk individuals SQ q1 wk or personal history ankylosing spondylitis, TNF-α inhibitor) (PPD/interferon gamma release of demyelinating juvenile idiopathic assay annually) disease (MS) arthritis for children ≥ 4 y Plaque psoriasis, Ustekinumab psoriatic arthritis, (­Stelara; anti-IL-12 SQ q90 d Crohn disease for and IL-23) children ≥ 12 y Secukinumab Plaque psoriasis, (Cosentyx; anti-IL-17 SQ q4 wk psoriatic arthritis, and IL-22) Same as above, ankylosing spondylitis plus risk of IBD Ixekizumab (Taltz; Psoriatic arthritis, SQ q2 wk anti-IL-17) plaque psoriasis Risk of infection, Same as above, plus PPD/interferon Guselkumab injection site history of IBD SQ q8 wk gamma release Plaque psoriasis (­Tremfya; anti-IL-23) reaction, GI assay effects

CBC, complete blood count; CHF, congestive heart failure; CMP, comprehensive metabolic panel; GI, gastrointestinal; HBV, hepatitis B virus; HCV, hepatitis C virus; IBD, inflammatory bowel disease; IL, interleukin; MS, multiple sclerosis; PPD, purified protein derivative; SQ, subcutaneous injection; TB, tuberculosis; TNF, tumor necrosis factor; URI, upper respiratory infection. sions have also appeared and grown across his ever, routine monitoring for myelosuppres- lower back, gluteal fold, legs, abdomen, and sion and hepatotoxicity is required. arms. He is now being evaluated by a rheu- ❚ Biologic therapy. When conventional matologist for worsening symmetric joint pain therapies fail, immune-targeted treatment that includes his lower back. with “biologics” may be initiated. As knowl- ❚ Methotrexate has been used to treat edge of signaling pathways and the immuno- psoriasis and psoriatic arthritis since the pathogenesis of psoriasis has increased, so 1950s. Methotrexate is a competitive inhibi- has the number of biologic agents, which are tor of dihydrofolate reductase and is typi- generally well tolerated and effective in man- cally given as an oral medication dosed once aging plaque psoriasis and psoriatic arthritis. weekly with folic acid supplementation on Although their use, which requires monitor- the other 6 days.17 The most common adverse ing, is handled primarily by specialists, famil- effects encountered with methotrexate are iarizing yourself with available agents can be gastrointestinal upset and oral ulcers; how- helpful (TABLE).22 CONTINUED

MDEDGE.COM/FAMILYMEDICINE VOL 69, NO 4 | MAY 2020 | THE JOURNAL OF FAMILY PRACTICE 199 ❚ Nutritional modification and sup- plementation in treating skin disease still References 1. Jackson R. John Updike on psoriasis. At war with my skin, from the requires further investigation. Fish oil has journal of a leper. J Cutan Med Surg. 2000;4:113-115. shown benefit for cutaneous psoriasis in 2. Gelfand JM, Weinstein R, Porter SB, et al. Prevalence and treatment 7,8 of psoriasis in the United Kingdom: a population-based study. Arch randomized controlled trials. Oral vitamin Dermatol. 2005;141:1537-1541. D supplementation requires further study, 3. Helmick CG, Lee-Han H, Hirsch SC, et al. Prevalence of psoriasis among adults in the U.S.: 2003-2006 and 2009-2010 National Health whereas selenium and B12 supplementation and Nutrition Examination Surveys. Am J Prev Med. 2014;47:37-45. 7 have not conferred consistent benefit. Giv- 4. Alexander H, Nestle FO. Pathogenesis and immunotherapy in cuta- neous psoriasis: what can rheumatologists learn? Curr Opin Rheu- en that several studies have demonstrated a matol. 2017;29:71-78. relationship between body mass index and 5. Fahlén A, Engstrand L, Baker BS, et al. Comparison of bacterial mi- crobiota in skin biopsies from normal and psoriatic skin. Arch Der- psoriatic disease severity, weight loss may matol Res. 2012;304:15-22. be helpful in the management of psoriasis as 6. Takeshita J, Grewal S, Langan SM, et al. Psoriasis and comorbid dis- well as psoriatic arthritis.8 eases: epidemiology. J Am Acad Dermatol. 2017;76:377-390. 7. Millsop JW, Bhatia BK, Debbaneh M, et al. Diet and psoriasis, part III: ❚ Other systemic agents—for indi- role of nutritional supplements. J Am Acad Dermatol. 2014;71:561- viduals who cannot tolerate the biologic 569. 8. Debbaneh M, Millsop JW, Bhatia BK, et al. Diet and psoriasis, agents—include acitretin, azathioprine, my- part I: impact of weight loss interventions. J Am Acad Dermatol. cophenolate mofetil, and cyclosporine.15,17 2014;71:133-140. 9. Bhatia BK, Millsop JW, Debbaneh M, et al. Diet and psoriasis, part II: celiac disease and role of a gluten-free diet. J Am Acad Dermatol. Paradoxical psoriatic reactions 2014;71:350-358. 10. Fry L, Baker BS. Triggering psoriasis: the role of infections and medi- Individualize When a psoriatic condition develops during cations. Clin Dermatol. 2007;25:606-615. therapy biologic drug therapy, it is known as a para- 11. Singh RK, Lee KM, Ucmak D, et al. Erythrodermic psoriasis: patho- physiology and current treatment perspectives. Psoriasis (Aukl). according to doxical psoriatic reaction. The onset of de 2016;6:93-104. novo psoriasis has been documented dur- 12. Garg A, Gladman D. Recognizing psoriatic arthritis in the dermatol- the severity of ogy clinic. J Am Acad Dermatol. 2010;63:733-748. disease, location ing TNF-α inhibitor therapy for individuals 13. McGonagle D, Hermann KG, Tan AL. Differentiation between os- with underlying rheumatoid arthritis.23 Skin teoarthritis and psoriatic arthritis: implications for pathogenesis and of the lesions, treatment in the biologic therapy era. Rheumatology. 2015;54:29-38. involvement biopsy reveals the same findings as common 14. Kim GK, Del Rosso JQ. Drug-provoked psoriasis: is it drug induced plaque psoriasis. or drug aggravated?: understanding pathophysiology and clinical of joints, and relevance. J Clin Aesthet Dermatol. 2010;3:32-38. comorbidities. 15. Kupetsky EA, Keller M. Psoriasis vulgaris: an evidence-based guide Using immunosuppressive Tx? for primary care. J Am Board Fam Med. 2013;26:787-801. 16. Helm MF, Farah JB, Carvalho M, et al. Compounded topical medi- Screen for tuberculosis cations for diseases of the skin: a long tradition still relevant today. Testing to exclude a diagnosis of latent or un- N Am J Med Sci. 2017;10:116-118. 17. Weigle N, McBane S. Psoriasis. Am Fam Physician. 2013;87:626-633. diagnosed tuberculosis must be performed 18. Helfrich YR, Sachs DL, Kang S. Topical vitamin D3. In: Wolverton SE, prior to initiating immunosuppressive therapy ed. Comprehensive Dermatologic Drug Therapy. 2nd ed. Philadel- phia, PA: Saunders; 2007:691-695. with methotrexate or a biologic agent. Tuber- 19. Lebwohl M, Siskin SB, Epinette W, et al. A multicenter trial of calci- culin skin testing, QuantiFERON-TB gold test, potriene ointment and halobetasol ointment compared with either agent alone for the treatment of psoriasis. J Am Acad Dermatol. and the T-SPOT.TB test are accepted screening 1996;35:268-269. modalities. Discordance between tuberculin 20. Pasch MC. Nail psoriasis: a review of treatment options. Drugs. 2016;76:675-705. skin tests and the interferon gamma release 21. Bagel J, Gold LS. Combining topical psoriasis treatment to en- assays in latent TB highlights the need for fur- hance systemic and phototherapy: a review of the literature. J Drugs Dermatol. 2017;16:1209-1222. ther study using the available QuantiFERON- 22. Rønholt K, Iversen L. Old and new biological therapies for psoria- TB gold test and the T-SPOT.TB test.24 JFP sis. Int J Mol Sci. 2017;18:e2297. 23. Toussirot É, Aubin F. Paradoxical reactions under TNF-alpha block- ing agents and other biologic agents given for chronic immune-me- CORRESPONDENCE diated diseases: an analytical and comprehensive overview. RMD Karl T. Clebak, MD, FAAFP, Penn State Health Milton Open. 2016;2:e000239. S. Hershey Medical Center, Department of Family and 24. Connell TG, Ritz N, Paxton GA, et al. A three-way comparison of tu- Community Medicine, 500 University Drive, Hershey, PA berculin skin testing, QuantiFERON-TB gold and T-SPOT.TB in chil- 17033; [email protected]. dren. PLoS One. 2008;3:e2624.

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