Ringworm

A 35-year-old African American man was seen for evaluation of his epilepsy. During the physical examination, the physician noticed the patient had dark spots on his abdomen and light spots on his back (Figures 1 and 2). Close inspection of the macules showed they were covered by a light scale. There were no lesions in his mouth or on his hands, feet, or genitals.

[FIGURES 1-2 OMITTED]

The man stated that these spots had appeared on his body on and off for many years. He reported no pain or itching. The rash worsened with sweating in the hot and humid summers of Florida. He had tried a "blue" (selenium sulfide) shampoo with only minimal success. The patient had not taken any antiepileptic medicines for 2 years, and he reported no recent seizures.

He was concerned that these spots were contagious because his girlfriend had developed some patches on her skin in the last month. He was not sure if it was the same thing, as her spots were not as noticeable as his. He said that he was in a monogamous heterosexual relationship and usually practiced safe sex.

* WHAT IS THE DIAGNOSIS?

Why are the patches of different colors?

The pattern of hypopigmented and brown macules on the trunk with a flue scale points to tinea versicolor (Figure 3). Versicolor means a variety of or variation in colors; the macules in tinea versicolor can be white, pink, and brown.

[FIGURE 3 OMITTED]

Laboratory confirmation

The scaling portion of the skin was scraped onto a slide. Potassium hydroxide with dimethyl sulfoxide was placed on the slide and covered with a coverslip. (Dimethyl sulfoxide helps the potassium hydroxide dissolve the skin cells faster.)

Microscopic examination revealed the typical "spaghetti and meatballs" pattern of tinea versicolor (Figure 4). The spaghetti are the hyphae and the meatballs are the spores of Pityrosporum ovale.

[FIGURE 4 OMITTED]

* MYCOLOGY AND VARIATIONS

Pityrosporum ovale is a lipophilic yeast that is part of the normal cutaneous flora in adults. However, it is associated with such skin diseases as Pityrosporum folliculitis, seborrhea, and tinea versicolor. P ovale (oval) is also called P orbiculare (round); it is the same organism with a different shape. The old name for this organism is Malassezia furfur.

Tinea versicolor is also called pityriasis versicolor--a better name, as it refers to the Pityrosporam species. The word tinea is generally applied to infections caused by dermatophyte fungi that are not yeastlike. The white and brown colors are secondary to damage to melanocytes caused by the Pityrosporum, while the pink is an inflammatory reaction to the organism.

Pityrosporum thrive on sebum and moisture; they tend to grow on the skin where there are sebaceous follicles secreting sebum. Tinea versicolor is found on the chest, abdomen, upper arms, and back; seborrhea tends to be seen on the scalp, face, and anterior chest. The prevalence of tinea versicolor is higher in the summer months, when patients may sweat more and have greater sun exposure, which highlights differences in skin color.

* DIFFERENTIAL DIAGNOSIS

The differential diagnosis includes pityriasis rosea, secondary syphilis, and tinea corporis.

Pityriasis rosea, an inflammatory Skin condition of unknown cause, exhibits with a fine collarette scale around the border of the lesions. The condition us-ally begins with a herald patch 2 to 7 cm in diameter.

Secondary syphilis, caused by the spirochete Treponema pallidum, causes rashes that are usually not scaly; macules usually appear on the palms and soles. Neither secondary syphilis nor pityriasis rosea would produce hyphae and spores on a potassium hydroxide scraping. If there is a suspicion of secondary syphilis, a Venereal Disease Research Laboratory test or rapid plasma reagin should be drawn.

Tinea corporis (ringworm of the body), caused by the fungus Trichophyton, is rarely widespread, and each individual lesion usually has central clearing and a well-defined, raised, scaling border. The potassium hydroxide preparation shows hyphae with multiple branch points rather than the "spaghetti and meatballs" pattern of tinea versicolor.

* TREATMENT

Because tinea versicolor is usually asymptomatic, treatment is generally for cosmetic reasons. In this case the patient was bothered by the spots and did not like being asked whether there was something wrong with his skin. Although it is not contagious, people often worry that it might be spread by bodily contact. His girlfriend could also have tinea versicolor simply because it is so common.

Topical treatments

The mainstay of treatment has been topical therapy. The therapies are usually antidandruff shampoos, because the same Pityrosporum species that cause seborrhea and dandruff also cause tinea versicolor. (1)

Patients may apply selenium sulfide 2.5% lotion/shampoo or zinc pyrithione shampoo to the affected areas daily for 1 to 2 weeks. A typical regimen involves applying the lotion or shampoo for 10 to 15 minutes and then washing it off in the shower (level of evidence [LOE]: 5). Another method involves applying the lotion for 24 hours before washing it off.

Ketoconazole 2% shampoo (Nizoral), used as a single application or daily for 3 days, is also safe and highly effective in treating tinea versicolor (LOE: 1b). (2) Topical antifungal creams can be used, but they will be more expensive if they have to be spread over large areas. For smaller areas, the topical antifungal creams that work best are ketoconazole and clotrimazole (LOE: 5).

Oral antifungal agents

Oral antifungal agents are easier for many patients than applying a topical preparation daily for 1 to 2 weeks. Physicians should find out whether patients have preexisting liver disease and warn them of the risk of liver toxicity before prescribing any systemic antifungal. Although the risk of liver toxicity is very small with a single oral dose, it should be remembered that most often the treatment is for cosmetic reasons.

In a recent randomized controlled trial in India, 181 patients with moderate to extensive tinea versicolor were given 1 of 4 oral regimens: ketoconazole 400 mg in a single dose (Category I), ketoconazole 200 mg/d for 10 days (Category II), fluconazole 400 mg in a single dose (Category III), or fluconazole 150 mg/wk for 4 weeks (Category IV). After 4 weeks of treatment, clinical cure was observed in 66.6% (Category I), 73.3% (Category II), 80% (Category III) and 59.9% (Category IV) of patients. When relapse occurred, the time period varied from 3 to 10 months. A single-dose 400 mg oral fluconazole provided the best clinical as well as mycological cure rate, with no relapse during 12 months of follow-up (LOE: 2b). (3)

In another study comparing oral fluconazole and oral ketoconazole, patients were randomly divided in 2 groups: group 1 received two 150-mg capsules of fluconazole in a single dose repeated weekly for 2 weeks; group 2 received two 200-mg tablets of ketoconazole in a single dose repeated weekly for 2 weeks. One hundred patients completed the study, and no major side effects were noted between the 2 treatment regimens. No significant differences in efficacy, safety, and tolerability were found between the 2 regimens (LOE: 2b). (4) Oral ketoconazole is less expensive than oral fluconazole, however, because it is available as a generic.

0ral itraconazole (Sporanox) has been shown to be safe and effective as a prophylactic treatment for tinea versicolor (LOE: 1b). (5) Itraconazole 200 mg given twice a day for 1 day a month improves mycologic outcomes. It probably improves clinical outcomes such as appearance, although there was not enough information to judge the clinical significance. (6)

* OUTCOME

The physician explained tinea versicolor to the patient. The patient was delighted that the physician wrote the name of the condition down for him on his prescription pad, and was happy to hear that it was not contagious. The benefits and risks of the treatment options were also explained.

The patient chose the single 400-mg dose of oral fluconazole because he did not have great success with the "blue" shampoo in the past. We chose the oral fluconazole over the ketoconazole because of the data showing fewer relapses. (3) Fortunately, he was not on any antiepileptic medications that would interact with oral antifungal agents. The patient was told he could use any over-the-counter dandruff shampoo if he began to see a recurrence of the tinea versicolor in the future (LOE: 5).

Patients should be told that the change in skin color will not reverse immediately. The first sign of successful treatment is the lack of scale. The yeast acts like a sunscreen in the hypopigmented macules. Sun exposure will hasten the normalization of the skin color in the patients with hypopigmentation.

REFERENCES

(1.) Usatine RP. What is in a name? West J Med 2000; 173:231-232.

(2.) Lange DS, Richards HM, Guarniefi J, et al. Ketoconazole 2% shampoo in the treatment of tinea versicoler: a multicenter, randomized, double-blind, placebo-controlled trial. J Am Acad Dermatol 1998; 39:944-950.

(3.) Bhogal CS, Singal A, Baruah MC. Comparative efficacy of ketoconazole and fluconazole in the treatment of pityriasis versicolor: a one year follow-up study. J Dermatol 2001; 28:535-539.

(4.) Farschian M, Yaghoobi R, Samadi K. Fluconazole versus ketoconazole in the treatment of tinea versicolor. J Dermatolog Treat 2002; 13:73-76.

(5.) Faergemann J, Gupta AK, Mofadi AA, et al. Efficacy of itraconazole in the prophylactic treatment of pityriasis (tinea) versicolor. Arch Dermatol 2002; 138:69-73.

(6.) Ebell ME. Itraconazole 1 day/month effective in tinea versicolor. Patient Oriented Evidence that Matters. From InfoRetriever [for palm OS]. Charlottesville, Va: InfoPOEMs, Inc., 2003.

Richard R Usatine, MD

Florida State University, Tallahassee

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