Hong Kong J. Dermatol. Venereol. (2013) 21, 15-21

Review Article

Swimmer's dermatoses

SC Ng and TS Cheng

Swimmer's dermatoses are not uncommon in dermatological practice with the increased popularity of swimming and aquatic leisure activities. There is a wide variety of dermatological conditions related to swimming or aquatic leisure activities, the exposed aquatic environment or their equipments. These include infections such as swimming pool granuloma caused by Mycobacterium marinum or cutaneous larva migrans, and non-infectious entities such as sea- bather's eruption or contact dermatitis to swimming equipment.

Keywords: Aquatic, dermatoses, swimmer, swimming

Introduction in 1896 in Athens.1 People swim in the swimming pool, fresh or salt water with their body immersed Swimming has been recorded since prehistoric in water for certain duration and exposed to times around 7000 years ago from Stone Age aquatic organisms and allergens or irritants in the painting. It is a popular leisure or sport nowadays, water or from the equipments, which can lead to and was part of the first modern Olympic Games cutaneous infection, allergic or irritant reactions. Skin infections caused by faecal organisms may be more common in contaminated rivers and skin Social Hygiene Service, Department of Health, irritation can occur from blue-green algae in Centre for Health Protection, Hong Kong inland waters. The use of communal changing

SC Ng, MBBS, MRCP(UK) room facilities may increase the risk of spread of TS Cheng, FHKCP, FHKAM(Medicine) warts and tinea pedis. Occasionally, unusual skin infections such as protothecosis can be acquired.2-4 Correspondence to: Dr. SC Ng Hence, swimmer's dermatoses are not uncommon Fanling Integrated Treatment Centre, 6/F, Fanling Health with a wide variety of entities as shown in Centre, 2 Pik Fung Road, Fanling, New Territories Table 1. 16 SC Ng and TS Cheng

Table 1. Classification of swimmer's dermatoses Infectious Non-infectious • Swimming pool granuloma or fish-tank granuloma • Sea bather's eruption caused by Mycobacterium marinum • Seaweed dermatitis caused by direct contact with • Swimmer's ear (acute or chronic otitis externa) Lyngbya majuscule • Swimmer's itch (cercarial dermatitis) • Sting by , sea lice and other stinging • Seal finger (Mycoplasma infection resulting from anemones seal bites to the hand) • Coral, sea urchin injuries • Cutaneous larva migrans • Contact dermatitis • Pseudomonas folliculitis and periporitis Bathing suits, goggles, snorkel masks, life jackets, • Others: cutaneous warts, tinea pedis, secondary sunscreen ingredient, water plants and inhabitants bacterial infection of wounds (e.g. Staphylococcus of the water aureus, Vibrio vulnificus), cellulitis, necrotising • Others: Sunburn, dry skin (swimmer's xerosis), fasciitis, protothecosis chlorine irritation and aquagenic acne, cold urticaria, aquagenic pruritus, abrasions from wetsuit folds, bikini bottom

Infectious entities of swimmer's laboratory media in 7-10 days if cultured at 30- dermatoses 33°C. i) Swimming pool granuloma or fish-tank Cutaneous infection with M. marinum requires a granuloma (Mycobacterium marinum portal of entry through the abraded skin. The infection) incubation period is about two to three weeks, Mycobacterium marinum is a slow growing and occasionally up to nine months. A solitary mycobacterium that causes disease in freshwater bluish-red inflammatory nodule or pustule and saltwater fish and sporadically in humans. appears at the inoculated site which then forms a The first human disease was reported in 1951, crusted ulcer, suppurative abscess or verrucous when the organism was found in granulomatous nodule. Lesions are most common on the skin lesions of individuals who swam in a dominant hand and fingers of fish fanciers, and contaminated swimming pool in Sweden. It is the on the elbows, knees and feet of swimmers. commonest atypical mycobacterial cutaneous M. marinum may present with a sporotrichoid infection.5-8 spread in approximately 20%-33% of cases9 and occasionally causes deeper infections The distribution of M. marinum is worldwide with (e.g. tenosynovitis, septic arthritis or rarely higher prevalence in temperate climates. Its osteomyelitis). The inhibition of M. marinum vectors include fresh or saltwater fish, snails, growth at 37°C accounts for its ability to shellfish, dolphins and water fleas. When cleaning infect the cooler body extremities; however, fish tanks at home or in the workplace (e.g. fish immunocompromised patients may have markets, restaurants), trauma to the hands may disseminated diseases. result in exposure to M. marinum. It can also be contacted from cracks in masonry, mud and even The histologic features range from non-specific chlorinated water, as this organism is fairly inflammation in the first few months to well-formed resistant to chlorine. It will grow on ordinary tuberculoid granulomas in older lesions with Swimmer's dermatoses 17 fibrinoid masses rather than caseation. Langhans' penetration. If the individual is not sensitised to giant cells are not always present, and intracellular the cercariae, lesions subside within 12 hours. acid-fast bacilli (longer and broader than tubercle Otherwise, lesions may evolve over 10-20 hours bacilli) are detectable in only about 10% of cases. in sensitised patients into intensely itchy papules, Epidermal changes including ulceration and which can coalesce into plaques and last 1-2 pseudoepitheliomatous hyperplasia may occur in weeks. In severe cases with repeated exposure to chronic lesions. cercariae, lesions may evolve into vesicles and pustules, and fever and headache can occur. Cultures are important to exclude other cutaneous sporotrichoid infections including leishmaniasis, Mild corticosteroid creams, calamine lotion or oral sporotrichosis and other atypical mycobacterial antihistamine can be beneficial for symptomatic infections (e.g. M. kansasii, M. chelonei). A positive relief. Cool compresses, baking soda or colloidal culture of M. marinum can be obtained in 70- oatmeal bathing have been recommended. 80% of cases if grown between 30 and 33°C. Antibiotics may be used to treat secondary Imaging should be considered to rule out deep infections and oral steroids can be considered in infection especially in treatment-refractory cases. severe reactions.

M. marinum is usually sensitive to clarithromycin, iii) Cutaneous larva migrans minocycline, doxycycline, amikacin, ciprofloxacin, This is a parasitic skin manifestation caused by moxifloxacin and trimethoprim-sulphamethoxazole.7 hookworm larvae that usually affect cats, dogs Based on in-vitro susceptibility and clinical response in and other . Humans can be infected by a 16 culture-positive case series, clarithromycin is the walking barefoot, sitting or lying unprotected on drug of choice for confirmed or suspected cases.9 sandy beaches that have been contaminated with Two agents should be considered for serious faeces. It is also known as creeping infections (e.g. clarithromycin and ciprofloxacin). eruption as the larvae migrate under the skin's The antibiotic(s) should be continued for one to surface and cause itchy red lines or tracks. The two months after resolution of symptoms, typically wandering thread-like line is about 3 mm wide, for a total of three to four months. Treatment commonly on the feet, hands and buttocks, in a failure is more usually related to involvement of bizarre and serpentine pattern.12 deeper structures than to the antibiotic regimen. Causes of creeping eruption include Ancylostoma ii) Swimmer's itch (cercarial dermatitis) brasiliense, A. caninum, A. ceylonicum, Uncinaria This follows penetration of the skin by cercariae stenocephala and Bunostomum phlebotomum. of avian schistosomes for which humans are not These are all hookworms of various animals, of the primary host. Swimmer's itch develops on an which the dog hookworm, A. brasiliense is the exposed area of skin 12-24 hours after contact commonest cause of creeping eruption in human. with these larvae forms, usually in fresh water, The larvae advance at a rate of a few millimetres when they mistakenly penetrate the person's skin to a few centimetres each day, and are somewhere instead of its usual host (e.g. duck).3 Outbreaks in front of the head of the track.13 are more common in temperate climates in summer. The risk is increased by the time spent in The disease can be clinically diagnosed and is the water and when there is an onshore wind.2,10,11 self-limiting. Larva currens (the urticarial weal caused by subcutaneous larvae of Strongyloides The initial symptom may be a prickling sensation stercoralis migrating several centimeters per hour), soon after leaving the water. Erythematous migratory myiasis (tortuous, thread-like red line macules appear 10-15 minutes after larval that ends in a terminal vesicle due to larvae of 18 SC Ng and TS Cheng flies of the genera Gasterophilius and Hypoderma) external auditory canal. Freshwater swimming and gnathostomiasis (intermittent, migratory, appears to be a particular risk factor. Failure to subcutaneous swellings) must be distinguished. dry the ears completely after swimming, Eighty-one percent of A. brasiliense lesions shampooing or showering may be contributory disappear in four weeks, while some persist for factors.15 many months. vi) Seal finger Ivermectin in a single dose of 200 µg/kg body Seal finger is a finger infection caused by weight is the main treatment, and albendazole Mycoplasma species (e.g. M. phocacerebrale) 400 mg/day by mouth for three days or topical through direct contact with seals, sea lions or application of 10% thiabendazole are alternatives. walruses. Traditionally an occupational hazard of seal hunters, but it is increasingly common in iv) Pseudomonas folliculitis and periporitis wildlife workers. Tetracycline for two to six weeks Inflatable swimming pools, Jacuzzis and hot tubs is the treatment of choice.3,16,17 may represent a particular hazard, even when the water inside is adequately disinfected. Pseudomonas aeruginosa is able to withstand Non-infectious entities of swimmer's relatively high temperatures and high chlorine dermatoses levels, and colonises the over-hydrated stratum corneum of the follicular ostia.2 i) Seabather's eruption First described in 1949 as a pruritic papular Symptoms usually occur 8-48 hours after eruption occurring in bathers off the eastern coast exposure. The rash is usually itchy and of Florida, this condition is believed to be a polymorphic, with erythematous macules, hypersensitivity reaction to the larval form of papules, pustules and vesicles and mostly affects thimble jellyfish, unguiculata or certain the bathing-suit area. There may be associated anemones (e.g. Edwardsiella lineata) trapped conjunctivitis, pharyngitis, and occasionally underneath the swimwear, in intertriginous areas swollen and painful breasts, abdominal symptoms or in the hair of the bather.3 It has also been and lymphadenopathy. reported in Mexico, the and in many tropical and sub-tropical waters. In Florida it is 'Pseudomonas hot foot syndrome' had been called 'Pica-Pica', the Spanish for 'Itchy-Itchy'.3,18-21 described as a distinctive painful nodular eruption on the soles of children who had been exposed to It is a seasonal dermatitis from March through P. aeruginosa in a heated wading pool with a grit- August and affects swimmers, snorkelers, or divers coated floor.14 soon after getting out of the water. The onset ranges from few hours to up to 24 hours since Treatment is symptomatic in uncomplicated cases. the sea bathing. Most patients (~98%) would have The lesions usually clear spontaneously over pruritic papules over the bathing suit area, which 7-10 days. are usually concentrated in tight-fitting areas and last for one to two weeks. Itching can be quite v) Swimmer's ear severe and the eruption may become painful. Otitis externa in swimmers is common in tropical Occasionally, 10-18% patients may have fever, and subtropical areas, especially among white malaise or other systemic symptoms (but up to people. Swimming, high temperature and high 40% with age <16). Children younger than 16 relative humidity encourage maceration and years old and surfers have a higher risk for secondary bacterial or fungal infections of the seabather's eruption. Swimmer's dermatoses 19

Wearing bathing suits for prolonged periods after iii) Jellyfish stings swimming, showering in fresh water and Jellyfish commonly have stinging nematocysts. mechanical stimulation (e.g. rubbing with a towel) They consist of a bell-shaped body with tentacles, may provoke the discharge of venom by the larvae within which the nematocysts reside. Stings are and make the eruption worse. Hence, bathers are delivered when contact is made with the tentacles advised to take off the bathing suits before and nematocysts discharge into the skin. showering in high prevalent areas. Jellyfish stings result in immediate pain as well as Topical corticosteroid (e.g. 1% hydrocortisone delayed and recurrent cutaneous reactions. cream), oral antihistamines and topical Erythematous, urticarial or haemorrhagic streaks antipruritics (e.g. calamine lotion or 0.5%-1% may be noticed. Confirmation of envenomation menthol) may improve the pruritus, while ice- can be obtained by tape-stripping of nematocysts pack or nonsteroidal anti-inflammatory drugs from the skin. A lichen planus-like eruption has may reduce the pain and inflammation. Oral been reported. Chironex fleckeri, the Pacific box prednisolone can be considered in severe jellyfish is generally considered the most reaction. dangerous species, and stings commonly result in shock. Storms often drive the jellyfish into ii) Seaweed dermatitis shallow water in great numbers and sea-bathing It is a skin rash caused by direct contact with a or surfing should be discouraged during extreme poisonous type of seaweed, most commonly the weather.3,21,23 blue-green alga, Lyngbya majuscula. It produces two toxins called lyngbyatoxin A and Avoidance is the best means of preventing injury. debromoaplysiatoxin. Fragments of seaweed When envenomation occurs in a swimmer, the are caught under the swimwear with its toxin victim should be immediately removed from the rubbing into the skin. The reaction may start a water to prevent drowning. Soaking the site in hot few minutes to a few hours after the swimmer but not scalding water (~40oC) will denature some leaves the water.22 of the venom proteins and sea water can be used to remove jellyfish tentacles. Antivenom is An itching and burning sensation followed by a available for some of the more toxic species. red, sometimes blistering rash occurs, sometimes Treatment with topical corticosteroids and in an entire swimsuit pattern. It often affects the calcineurin inhibitors may be helpful for delayed scrotum in men and inframammary folds in reactions. Tropical jellyfish sting inhibitors, females, depending on the type of swimwear including lotions combined with sunscreens, are used. Symptoms typically last for four to 48 hours. available as over-the-counter products to Sometimes, the affected person can have inactivate jellyfish stinging cells. periorbital and perioral swelling, with or without the rash. iv) Sea urchin injuries Envenomation by sea urchins produces immediate The affected individual should remove the swimsuit burning pain, which can be very intense and lasts immediately and wash the skin vigorously with for several hours. The degree of local swelling is soap and water. The eruption can be treated as a sometimes severe. Immediate treatment consists sunburn using wet towels and soothing creams of careful removal of spines and pedicellariae and (e.g. calamine). Mild topical corticosteroids can immersion of the affected area in hot water to be considered but in severe reactions, systemic relieve the pain. Erbium-yttrium-aluminium-garnet steroids are needed. (Er:YAG) laser ablation has proved effective to 20 SC Ng and TS Cheng remove the spines and can be considered in injury', rope burns on the extremities of water difficult cases.24 skiers, 'purpura gogglorum' caused by the effects of pressure and suction, water-slap injuries on the The puncture wounds heal within one to two weeks anterior thighs of speed swimmers, and 'swimmer's if there is no secondary infection. Implantation shoulder'-an erythematous rough plaque caused epidermoid cysts may develop from fragments of by friction from the unshaven chin while swimming epithelium driven into the wounds by the sea freestyle.2 urchin spines. viii) Bikini bottom Delayed granulomatous reactions (foreign-body A nodular folliculitis of the inferior buttocks, or sarcoidal type) usually develop several months probably caused more by follicular occlusion from after the injury with bluish papules or nodules not changing out of a damp swimsuit than by appearing at the site of penetration by the spines. specific pathogens.2 These lesions are very persistent if untreated, and treatment by intralesional steroids can be considered. It has been suggested that M. marinum Conclusion may play a pathogenic role in some case of sea urchin granuloma and that this cause should be The type of hobbies and travel are important but ruled out.21 commonly neglected clues in history taking in daily clinical practice. Although most swimmer's v) Coral injuries dermatoses are not life-threatening and some are Envenomation by fire corals usually produces self-limiting, we should complete our history taking immediate burning or stinging pain, followed by with hobby and recent travel to achieve a prompt urticarial lesions at the contact site. These may diagnosis and appropriate treatment. For evolve into a localised vesico-bullous eruption, example, with increasing international travel, sea and subsequently to a chronic granulomatous, bather's eruption may still be encountered in the lichenoid lesion.21 traveler returning from Florida or the Caribbean.

The lesions should be rinsed with seawater. Fresh water will increase the pain and therefore should References be avoided. Topical acetic acid (vinegar) or isopropyl alcohol can then be applied to inactivate 1. Wikipedia contributors. Swimming (sport). Wikipedia, the venom, followed by removal of the The Free Encyclopedia; 2013 [updated 6 February nematocysts with tweezers or tape, and 2013; cited 6 February 2013]. Available from: http:// en.wikipedia.org/w/index.php?title=Swimming_(sport) immobilisation of the extremity. Topical steroids &oldid=536922051. can be used as needed for itching. 2. Kennedy CTC, Creamer D. Skin hazards of swimming and diving. In: Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook’s Textbook of Dermatology, 8 ed. West vi) Contact dermatitis Sussex: Wiley-Blackwell; 2010, p.28.53-6. Allergic contact dermatitis can occur, for example 3. Elston DM. Marine injuries. In: Bolognia JL, Jorizzo JL, to the elastic or dyes of swimming costume, Schaffer JV, editors. Dermatology, 3 ed. Elsevier goggles, snorkel masks or mouthpieces. Rarely, Saunders; 2012, p.1451-3. 4. Trizna Z. Cutaneous Manifestations Following Exposures a toxic leucoderma has been reported from the to Marine Life. Medscape; 2013 [updated Jan 9, 2013; use of goggles.2 cited 4 Februrary 2013]. Available from: http:// emedicine.medscape.com/article/1089144-overview. vii) Physical trauma 5. Yates VM. Non-tuberculous (atypical) mycobacteria. In: Burns T, Breathnach S, Cox N, Griffiths C, editors. Physical trauma to the skin include 'surfer's knee Rook's Textbook of Dermatology, 8 ed. West Sussex: Swimmer's dermatoses 21

Wiley-Blackwell; 2010, p.31.0-3. 345:335-8. 6. Ramos-e-Silva M, Ribeiro de Castro MC. Non- 15. Kennedy CTC. External otitis. In: Burns T, Breathnach S, tuberculous mycobacterioses. In: Bolognia JL, Jorizzo Cox N, Griffiths C, editors. Rook's Textbook of JL, Schaffer JV, editors. Dermatology, 3 ed. Elsevier Dermatology. 8 ed. West Sussex: Wiley-Blackwell; 2010, Saunders; 2012, p.1235-42. p. 68.20-5. 7. Wagner D, Young LS. Nontuberculous mycobacterial 16. Lewin MR, Knott P, Lo M. Seal finger. Lancet 2004;364 infections: a clinical review. Infection 2004;32:257-70. (9432):448. 8. Wentworth AB, Drage LA, Wengenack NL, Wilson JW, 17. White CP, Jewer DD. Seal finger: A case report and Lohse CM. Increased Incidence of Cutaneous review of the literature. Can J Plast Surg 2009;17: Nontuberculous Mycobacterial Infection, 1980 to 2009: 133-5. A Population-Based Study. Mayo Clin Proc 2013;88: 18. Freudenthal AR, Joseph PR. Seabather's Eruption. N Engl 38-45. J Med 1993;329:542-4. 9. Dodiuk-Gad R, Dyachenko P, Ziv M, Shani-Adir A, Oren 19. Kumar S, Hlady WG, Malecki JM. Risk factors for Y, Mendelovici S, et al. Nontuberculous mycobacterial seabather’s eruption: a prospective cohort study. Public infections of the skin: A retrospective study of 25 cases. Health Rep 1997;112:59-62. J Am Acad Dermatol 2007;57:413-20. 20. Rademaker M. Sea bather's eruption. DermNet NZ; 10. Rademaker M. Swimmer's itch. DermNet NZ; 2004 2004 [updated 28 June 2011; cited 4 February 2013]. [updated 13 January 2012; cited 3 February 2013]. Available from: http://www.dermnetnz.org/arthropods/ Available from: http://www.dermnetnz.org/arthropods/ sea-bathers.html. swimmers-itch.html. 21. Burns T. Other noxious or venomous invertebrates. In: 11. Vega-Lopez F, Hay RJ. Cercarial dermatitis. In: Burns T, Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook's Breathnach S, Cox N, Griffiths C, editors. Textbook of Textbook of Dermatology, 8 ed. West Sussex: Wiley- Dermatology, 8 ed. West Sussex: Wiley-Blackwell; 2010, Blackwell; 2010, p.38.55-9. p.37.22-3. 22. Rademaker M. Seaweed dermatitis. DermNet NZ; 2004 12. Ngan V. Cutaneous larva migrans. DermNet NZ; 2003 [updated 15 June 2009; cited 4 February 2013]. [updated 2 Februry 2013; cited 3 Februry 2013]; Available from: http://www.dermnetnz.org/dermatitis/ Available from: http://www.dermnetnz.org/arthropods/ plants/seaweed.html. larva-migrans.html. 23. Tallon B. Marine wounds and stings. DermNet NZ; 2005 13. Vega-Lopez F, Hay RJ. Cutaneous larva migrans. [updated 1 July 2011; cited 4 February 2013]. Available In: Burns T, Breathnach S, Cox N, Griffiths C, editors. from: http://www.dermnetnz.org/reactions/marine. Textbook of Dermatology, 8 ed. West Sussex: Wiley- html. Blackwell; 2010, p.37.16-7. 24. Boer A, Ochsendorf FR, Beier C, Kaufmann R. Effective 14. Fiorillo L, Zucker M, Sawyer D, Lin AN. The removal of sea-urchin spines by erbium: YAG laser Pseudomonas Hot-Foot Syndrome. N Engl J Med 2001; ablation. Br J Dermatol 2001;145:169-70.