Are You Confident of the Diagnosis?
What you should be alert for in the history
History is suggestive when an individual reports an asymptomatic or minimally pruritic eruption that appears and/or recurs on the upper trunk and proximal arms, areas rich in sebaceous glands, in warm weather months.
Characteristic findings on physical examination
The rash consists of generally symmetric individual and confluent hypo- or hyperpigmented (classically fawn-colored) occasionally pink, round, or oval patches or thin plaques; often with superficial fine, grainy scale (Figure 1, Figure 2, Figure 3). All affected areas typically are the same color in any given individual.
Expected results of diagnostic studies
Potassium hydroxide (KOH) exam usually readily reveals abundant characteristic spores and short curly hyphae, referred to as “spaghetti and meatballs” or “bacon and eggs” (Figure 4). Woods light exam may be used to highlight extent of disease.
Biopsy rarely is necessary and shows abundant hyphae and spores in the stratum corneum. Likewise, culture generally is not necessary and requires special medium with the addition of olive oil to Sabouraud’s medium.
A negative KOH exam should elicit a differential diagnosis. Possible diagnoses include:
– Confluent and reticulated papillomatosis of Gougerot and Carteud (CARP). CARP is often indistinguishable from tinea versicolor. The diagnosis may be supported by biopsy findings and clinical response of CARP to treatment with minocycline.
– Vitiligo macules and patches are depigmented rather than hypo- or hyperpigmented and are not scaly; distribution of lesions is not typically similar to that of tinea versicolor.
– Terra firma-forme dermatosis is characterized by hyperpigmented patches (“dirty-appearing skin”), most commonly on the neck, and occasionally on the arms or trunk, which wipe off with isopropyl or 70% ethyl alcohol. Soap and water is ineffective.
– Pityriasis rosea (PR). PR starts with a “herald patch” days before onset of the generalized eruption; the eruption consists of thin flesh-colored or pink oval plaques with a trailing collarette of scale, typically in a “Christmas tree” distribution on the trunk and proximal extremities. PR usually resolves spontaneously in 4-8 weeks.
– Secondary syphilis may mimic pityriasis rosea except usually there is no herald patch. Syphilis may be preceded several weeks to 2 months by a genital or other chancre. There are often constitutional symptoms such as low-grade fever, malaise, pharyngitis, myalgias, and headaches, as well as lymphadenopathy and other mucocutaneous signs of secondary syphilis such as mucous patches and condyloma lata.
A characteristic biopsy finding is dermal inflammation rich in plasma cells. Serologic studies such as rapid plasma reagin (RPR) and fluorescent treponemal antibody-absorption (FTA-ABS) confirm the diagnosis.
– Pityriasis alba generally presents as small, ill-defined, hypopigmented plaques with fine scale in atopic individuals, usually children. Most commonly the plaques appear on the face with occasional involvement of the upper arms and shoulders; rarely they appear elsewhere.
– Tinea corporis appears as asymptomatic or pruritic red annular plaques with fine scale, usually relatively localized but occasionally extensive. Diagnosis may be confirmed by KOH exam showing long thin branching hyphae, or by culture on Sabouraud’s medium. Biopsy rarely is needed.
– Progressive macular hypomelanosis consists of nonscaly hypopigmented macules on the trunk of young adults, typically in patients of African-American lineage. KOH exam is negative. This condition is likely due to the presence of Propionibacterium acnes altering melanogenesis. Treatment directed toward the bacteria may be effective.
Who is at Risk for Developing this Disease?
This dermatosis is most common in adolescents and young adults, although it may occur at any age, and is most prevalent in tropical and temperate climates, where high temperatures and humidity promote overgrowth of the causative organism.
Pregnancy, immunosuppression, malnutrition, genetic predisposition, and high serum cortisol levels (either endogenous or exogenous) may predispose to the condition.
What is the Cause of the Disease?
Tinea versicolor is a common superficial fungal infection of the stratum corneum caused by the lipophilic yeast Malassezia furfur (Pityrosporum orbiculare).
This organism is part of the normal skin flora, especially in areas of sebaceous prominence, and conditions such a high heat and humidity or other predisposing factors allow for their proliferation and the appearance of the rash.
Systemic Implications and Complications
Wile tinea versicolor is primarily a cosmetic concern, there are rare reports of catheter-associated Malassezia furfur sepsis in neonates receiving lipid infusions and in immunocompromised adults.
Treatment options include:
– Selenium sulfide shampoo 2.5%, ketoconazole shampoo 2%, or zinc pyrithione shampoo. Apply to the entire skin surface on neck, trunk, and proximal extremities for 5 to 10 minutes daily for 1 to 4 weeks.
– Imidazole antifungal creams or lotions (oxiconazole, econazole, miconazole, clotrimazole, ciclopirox). Oxiconazole cream is the only FDA-approved treatment for tinea versicolor. Apply once or twice daily for 1 to 4 weeks. Allylamines are ineffective.
– Sodium thiosulfate 25% (Tinver), apply twice a day for 2 to 4 weeks. Use is limited by its odor and irritant potential.
– Sulfur-salicylic shampoo (Sebulex), apply overnight for 1 week
– Ketoconazole 200mg/day10 days or 400mg single dose
– Itraconazole 200mg/day for 1 week
– Fluconazole 300mg/week for 2 to 4 consecutive weeks
– 3%-6% salicylic acid preparations, apply overnight for 1 to 2 weeks; usually effective but may be irritating
Optimal Therapeutic Approach for this Disease
Typically, treatment is initiated with one of the topical modalities. The antifungal creams or the shampoos are roughly equally effective and the choice may be based on patient preference. Longer durations of treatment correlate with higher cure rates.
Treatments are generally well tolerated but may cause skin irritation or contact dermatitis. Response to treatment should be within weeks. The eruption may recur and may be retreated in the same fashion.
Any of the oral antifungal agents noted above are usually effective, but are used as second- or third-line treatment options because of the potential for hepatotoxicity (low) and concern regarding interactions with other drugs.
It is important to inform the patient of the following:
– The causative organism is part of the normal skin flora and cannot completely be eliminated; thus, the rash often recurs, especially in warm weather.
– Even if prescription medications are used, over-the-counter options can be used to eliminate the necessity of an office visit every time the rash recurs.
– Since the causative yeast is part of the normal skin flora, it is not contagious.
– The appearance of the rash may take weeks to improve after treatment. Any hypopigmented patches will not fade until the individual’s tan fades or until he/she receives further sun exposure to help the lighter patches blend in.
– Follow-up for repeat KOH exam may be useful to determine effectiveness of treatment, but usually is not necessary.
– To minimize or prevent recurrences, patients should avoid application of topical oils and may apply ketoconazole shampoo 2% or selenium sulfide shampoo or lotion 2.5% to all susceptible areas for 10 minutes prior to bathing once a month. Patients may also use zinc pyrithione (ZNP Bar) soap once or twice a week when bathing.
– Ketoconazole 2% or selenium sulfide shampoo 2.5% for the scalp once or twice a week may lower the yeast load and decrease recurrence rates as well.
– Ketoconazole 400mg once a month may be used prophylactically if topical prophylaxis fails.
Unusual Clinical Scenarios to Consider in Patient Management
If KOH exam is negative in a case of suspected tinea versicolor in an individual of color, consider progressive macular hypomelanosis in the differential diagnosis and consider therapy directed at Propionibacterium acnes.
Malassezia sp. have been recognized potentially to be an aggravating factor in several scenarios involving atopic dermatitis. Specifically, consider when atopic dermatitis primarily involves the head and neck, worsens during adolescence or early adulthood, or is refractory to conventional treatment. A 1 to 2 month course of systemic itraconazole or ketoconazole followed by weekly long-term prophylaxis may be helpful.
What is the Evidence?
Duncan, WC, Tschen, JA, Knox, JM. “Terra firma-forme dermatosis”. Arch Dermatol. vol. 123. 1987. pp. 567-9. (Hyperpigmented macules and patches mimicking tinea versicolor)
Delaney, MD, Lountzis, N, Ferringer, T. “Progressive macular hypomelanosis”. J Am Acad Dermatol. vol. 62. 2010. pp. AB120(Hypopigmented truncal macules, typically occurring in young adults of color)
Rowen, JL. “Fungal infections in the neonatal intensive care unit”. Semin Pediatr Infect Dis. vol. 12. 2001. pp. 107-14. (Rare cases of catheter-related Malassezia infections have been reported in neonates receiving lipid infusions.)
Garcia, CR, Johnston, BL, Corvi, G, Walker, LJ, George, WL. “Intravenous catheter-associated Malassezia furfur fungemia”. Am J Med. vol. 83. 1987. pp. 790-2. (This complication is rarely reported in immunocompromised hosts.)
Hu, SW, Bigby, M. “Pitryriasis versicolor: a systematic review of interventions”. Arch Dermatol. vol. 146. 2010. pp. 1132-40. (Tinea versicolor therapies are summarized.)
Borelli, D, Jacobs, PH, Nall, L. “Tinea versicolor: epidemiologic, clinical, and therapeutic aspects”. J Am Acad Dermatol. vol. 25. 1991. pp. 300-5. (A comprehensive review of this dermatosis)
Drake, LA, Dinehart, SM, Farmer, ER, Goltz, RW, Graham, GF, Hordinsky, MK. “Guidelines of care for superficial mycotic infections of the skin: pityriasis (tinea) versicolor”. J Am Acad Dermatol. vol. 34. 1996. pp. 287-9. (Comprehensive review of tinea versicolor treatment options)
Darabi, K, Hostetler, SG, Bechtel, MA, Zirwas, M. “The role of Malassezia in atopic dermatitis affecting the head and neck of adults”. J Am Acad Dermatol. vol. 60. 2009. pp. 125-36. (A detailed overview of the potential role of Malassezia in the exacerbation of atopic dermatitis)
Copyright © 2017, 2013 Decision Support in Medicine, LLC. All rights reserved.
No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.