Aetiological changes of tinea capitis in the Hubei area in 60 years: Focus on adult tinea capitis

BACKGROUND

Tinea capitis is a common dermatophyte infection of the scalp primarily affecting children, with less frequent, though not rare, observation in adults.

OBJECTIVE

This study aimed to assess changes in the causative agents of adult tinea capitis over a 60-year period in the Hubei area.

METHODS

A retrospective, single-centre study was performed on 164 adults with tinea capitis between 1960 and 2020.

RESULTS

Out of 1113 cases of tinea capitis, 164 patients were adults, representing 14.7% of all patients. Adult tinea capitis was slightly more prevalent in males (91, 55.5%) than in females (73, 44.5%), but gender difference was not statistically significant between adults and children. Adult tinea capitis was most prevalent between the ages of 18 and 29 years, with a mean age of 22 years. Trichophyton schoenleinii was the most common dermatophyte in adult tinea capitis (78, 47.6%), followed by Trichophyton violaceum (58, 35.4%). Most adult tinea capitis cases before the 1980s were caused by T. schoenleinii, but T. violaceum has become the leading pathogen for recent adult tinea capitis cases.

CONCLUSION

Tinea capitis is not a disease exclusive to children. On the contrary, an upward trend of tinea capitis in adults has been observed in recent years. T. violaceum has become the dominant causative agent of adult tinea capitis in the Hubei area, replacing T. schoenleinii. These results provide a better understanding of the treatment and prevention of tinea capitis in adults.

Tinea Capitis by Microsporum canis in an Elderly Female with Extensive Dermatophyte Infection

Tinea capitis is a type of dermatophyte infection primarily affecting children. We report a case of an elderly woman with well-controlled diabetes mellitus presenting with a six-month history of erythema with yellow crusts on her scalp and extensive erythematous patches with scales on the body skin. She adopted a stray cat before the disease onset. Dermoscopic findings and manifestation under the Wood's lamp favoured the diagnosis of tinea capitis. Further microscopic examinations of her scalp, including direct KOH and fluorescence stain examination, fungal culture and polymerase chain reaction sequencing identification confirmed the diagnosis of tinea capitis caused by Microsporum canis. Treatment with oral terbinafine was effective. Adult tinea capitis is often misdiagnosed due to its rarity and atypical presentation. However, in some regions, the incidence of tinea capitis in immunocompetent adults is rising which requires the awareness of clinicians. A thorough history (including the animal contacting history), physical examination and further mycological examinations are required for diagnosis. Trichophyton violaceum is the most common dermatophyte species in most regions while adult tinea capitis caused by Microsporum canis is less common. Terbinafine, griseofulvin and itroconazole have been reported to be effective drugs for the treatment of tinea capitis, and terbinafine can be considered as systemic treatment in elderly patients with comorbidities to reduce the drug-drug interaction.