Tinea capitis in Adults: Misdiagnosis or Reappearance?

Abstract

Background: According to the literature, tinea capitis in adults is supposed to be rare; we have recently observed a significant increase in cases. Methods: Epidemiological, clinical and mycological features were studied in all adult tinea capitis diagnosed over 1 year in our department. Results: Eight cases were observed: 75% of them were women, 50% never traveled and 62.5% had an underlying immunosuppressive disease. Scalp scaling and alopecia were the most frequent clinical features. A zoophilic dermatophyte was recovered in 50% of cases. Conclusion: These cases represent 11% of all tinea capitis observed in the same period of time (higher than the 3–5% observed in the literature). Secretion of sebum and colonization by Pityrosporon orbiculare are supported to protect the scalp against dermatophytic invasion after puberty, but an immune defect may also facilitate hair invasion. The erroneous notion of the disease being uncommon and the frequent atypical clinical presentation require a high degree of clinical suspicion.

Tinea Capitis in Adults

“…We found a relative frequency of 2.6%; this data agrees with literature [2,4], even if there are reported cases of a higher prevalence [13]. The relative resistance of adult's hair to colonization by dermatophytes, probably due to the fungistatic properties of the long chains fatty acids of the sebum produced after puberty and unknown immunological factors, could explain the rareness of cases in the elderly [2,4,6].…”

Relapsing Tinea capitis by Microsporum canis in an Adult Female Renal Transplant Recipient

“…Unlike pediatric forms, in immunocompetent adults tinea capitis is unusual and frequently characterized by unexpected clinical features, with little inflammation and scant hair loss [12]. At any age, M. canis is the most common causative agent of tinea capitis in Europe [13].…”

“…M. canis is more resistant to antifungal therapy; therefore, a prolonged treatment and an increased dosage are often necessary to obtain complete recovery, especially in immunosuppressed patients [12, 14]. …”

“…Given that a carrier condition is well known [12], it is hard to ascertain whether there were two reinfections in consequence of renewed exposure to the causative organism or whether two relapses occurred in spite of prolonged systemic therapy. However, the recurrence of an infrequent infection in the same host cannot be accidental.…”

Tinea Capitis: An Adult Invasion of a Childhood Scourge

“…Dermatophyte infection of the scalp usually ceases at puberty due to increase in the fungistatic saturated fatty acid production as demonstrated by Rothman et al [8]. The thick caliber of adult human hair is also protective against dermatophyte invasion [9]. These features decrease the physician's index of suspicion of tinea capitis infection in adults [6].…”