An unusual case of tinea capitis caused by Trichophyton schoenleinii in an elderly female.

Sir,

Tinea capitis occurs worldwide and commonly involves young children; <3% of its cases have been reported in the elderly. Improved standards of living in the developing countries after the Second World War has been associated with almost complete disappearance of many anthropophilic dermatophytes including Trichophyton schoenleinii. The “favic” type of tinea capitis classically caused by T. schoenleinii presents with yellowish cup shaped crusts called “scutula.”[1] The black dot variant has never been reported with T. schoenleinii till date. Herein we report a case of “black dot” variety of tinea capitis from the Pune district of Maharashtra, India.

A 70-year-old female presented with complaints of a markedly itchy scalp along with broken and unevenly growing hair since last two years. She denied contact with infected children, family members or pets. There was no history of plucking of hair or inland travel to places known to be endemic for tinea capitis. Examination of the occipital and right parietal scalp revealed patchy hair loss with broken hair shafts and black dot appearance [Figure 1]. The hair was of irregular length. There was no evidence of any dermatophytoses or other dermatoses anywhere else on the body. The patient was not hypertensive, diabetic, HIV-positive, or on any immunosuppressive drug. KOH mount showed fungal hyphae which revealed grey green fluorescence on Wood's light examination.[2] Based on the culture findings of slow growing, glabrous, off-white colonies with a folded surface, a characteristic crack in the agar medium [Figure 2a], visualization of a brown reverse pigment [Figure 2b] along with microscopic appearance of knobby, antler-like hyphae (favic chandelier) [Figure 3], the isolate was identified as T. schoenleinii. The patient was placed on the oral griseofulvin 375 mg twice a day, levocetirizine 5 mg twice a day and cetrimide shampoo thrice a week. The rationale of using cetrimide shampoo was to give antiseptic coverage to the patient keeping in mind the low hygiene status and few erosions caused on the scalp by vigorous scratching.

Figure 1

Black dot appearance on the scalp

Figure 2

(a) Slow growing off-white glabrous colonies with a folded surface and characteristic crack in the agar medium. (b) Reverse brown pigment

Figure 3

Knobby, antler-like hyphae with characteristic “favic chandelier” appearance. Lactophenol cotton blue stain was used and the growth observed under, ×40

The above mentioned low prevalence rate of tinea capitis in adults is accounted for by the presence of fungistatic saturated fatty acids in postpubertal sebum, competitive interference by Pityrosporum ovale and thicker caliber of hair.[3] Predisposing factors for sporadic tinea capitis in adults could to be immunosuppression or HIV, another source of fungal infection over the body, contact with children and/or zoophilic sources like pets.[3] Though a rare dermatophyte in India, a few endemic pockets of T. schoenleinii infection exist in Northwestern Indian states of Kashmir valley, Punjab and Rajasthan;[4] a few sporadic cases of its classical favic infection have also been reported from Haryana, Udaipur and South India.[456] The occurrence of black dot in our case from Pune suggests the possibility of sporadic foci of infection. Hence a high index of clinical suspicion and speciation by culture prior to initiation of therapy is essential in all cases presenting with patchy alopecia, uneven hair growth, scaling and crusting, irrespective of their age.