Tinea versicolor

Tinea versicolor is part of the normal flora of the skin. It is more common in adolescents and young adults who have higher sebum production than other age groups. The rash (papules and plaques with fine scales on the upper trunk and proximal arms) may be apparent only during the summer months.

CASES/YEAR
17,400 (US); 348,000 (Global)
CATEGORY
Localized Infections
AGENT TYPE
Fungi (Pathogenic Yeasts)
OTHER NAMES
Skin infection by Malassezia species; Pityriasis versicolor;
ACUITY
Subacute/Chronic
INCUBATION
Normal flora in 90% to 100% of people; [ABX Guide]
INITIAL SYMPTOMS
Hypopigmented or hyperpigmented, scaly papules and plaques on the trunk and proximal upper extremities that may be pruritic; [ID, p. 1173]
PRECAUTIONS
COMMENTS
The fungus is part of the normal flora of the skin, so it is not contagious. The condition is more common in adolescents and young adults who have higher sebum production than other age groups. The rash (papules and plaques with fine scales on the upper trunk and proximal arms) may be apparent only during the summer months. Recurrence can be prevented by treating topically once a month. Hypopigmentation may take months to resolve. [ID, p. 1174] For prophylaxis of recurrence in summer months, use Selsun or Nizoral shampoo (rub in & rinse off in 5-10 min) once a week. [ABX Guide] Malassezia species also causes folliculitis and seborrheic dermatitis (cradle cap and dandruff). [Harrison ID, p. 1029-30] Malassezia furfur may also cause folliculitis in immunosuppressed patients with diabetes, neutropenia, AIDS, and corticosteroid administration. [PPID, p. 1286, 3209]
DIAGNOSTIC
KOH prep: Short hyphae and spores with appearance of "spaghetti and meatballs"; Culture requires special oil-containing medium; [ID, p. 1174] Shows yellowish fluorescence under Wood's light in 1/3 of cases; [ABX Guide]
SCOPE
Global, but more common in warm humid climates; [ABX Guide]
SIGNS & SYMPTOMS
  • S papules or plaques
  • S pustule
ANTIMICROBIC

Yes

VACCINE

No

ENTRY
RESERVOIR
Human
RISK FACTORS
  • AIDS patients
  • Cancer patients
DRUG LINK
Merck Manual: Tinea Versicolor
REFERENCES FOR CASES/YEAR
1. (US) !/20 X global cases/yr;
2. (Global) Tinea versicolor in 2% of dermatomycoses cases in Japan in 2006; Using incidence results from study in New Zealand in 2003 showing 2900 cases of dermatomycoses per million; 0.02 X 2900 = 58 cases per million; 58 X 300 million = 17400 cases/year (US); 58 X 6000 million = 348,000 cases per year (worldwide); [PMID 23149353 & 14616492]