Tinea capitis caused by Trichophyton tonsurans among adults: Clinical characteristics and treatment response

Abstract

Background: Trichophyton tonsurans tinea capitis has become a growing epidemiological concern. Yet, its clinical manifestations and treatment response, specifically among adults, have only been described among small sample size studies.Objective: To assess clinical manifestations and treatment outcome of T. tonsurans tinea capitis among adults. Patients and Methods:A retrospective cohort study was carried out among 111 adults with T. tonsurans tinea capitis. Diagnosis was confirmed by fungal culture or polymerase chain reaction. Examinees' demographics, disease characteristics and treatment response were measured. The risk factors for the treatment failure were evaluated. Results:The mean age was 20.1 years (±3.1), with men (98.2%) outnumbering women.The follow-up lasted 12.2 months (±5.6). The majority of T. tonsurans tinea capitis was seen in the occipital area (87.6%). In 78.9% of the cases, the scalp manifestation was non-inflammatory (scaly plaques and papules:76.1% and seborrhoea-like: 2.8%).21.1% of cases presented with inflammatory tinea capitis (21.1%; Kerion: 10.1% and pustular: 11%). Concomitant involvement of other than scalp areas was common: tinea corporis was seen in 38.7% of the cases; tinea faciei and barbae in 24.3%; nape and anterior neck in 76.6% and 2.7% of the cases, respectively. An adequate treatment course with oral terbinafine resulted in 83.2% clinical cure rate. Treatment failure was significantly associated with concomitant tinea corporis (odds ratio 3.9; 95% confidence interval 1.3-12.1, p-Value< .02). Conclusion:The most common clinical presentation of T. tonsurans tinea capitis included occipital scaly plaques and papules with concomitant non-scalp lesions. Oral terbinafine was found to be highly effective. Concomitant tinea corporis increased the risk for treatment failure.

Comprehensive Review of Tinea Capitis in Adults: Epidemiology, Risk Factors, Clinical Presentations, and Management

“…In a sub-analysis among patients who failed treatment vs. those who were clinically cured, patients who failed treatment were more likely to also have tinea corporis (50% vs. 20.3%, OR 3.9, 95% CI 1.3-12.1, p < 0.02). Notably, the location and clinical subtype of TC infection were not associated with treatment failure or success [37]. In a retrospective study of 26 adult and pediatric patients with non-inflammatory M. canis TC confirmed by microscopy and culture, including four adult women aged 62-75 years, treated with terbinafine 250 mg/day, all adult patients achieved complete cure in 8 weeks without evidence of relapse, suggesting that a course of terbinafine for 8-12 weeks is an acceptable alternative for TC treatment in adults who have contraindications to griseofulvin [76].…”

“…Circumstances in which people are in close contact with infected persons or belongings promote TC infection. Crowded living conditions, including group homes and army barracks, contact with infected children, contact sports, and using shared gym or swimming pool facilities are common situations in which persons may be exposed to dermatophyte infections [8,19,26,32,[34][35][36][37]. In the case series of an M. canis TC infection outbreak involving six patients in Belgium by Hillary et al, the patients lived in close proximity inside of the same nursing home, highlighting the potential for human-to-human transmission among older adults [23].…”

“…This creates the appearance of black dots on a patch of bald scalp, leading to the common name "black dot ringworm" [49]. In a retrospective study of 111 adults with T. tonsurans tinea capitis confirmed by fungal culture or PCR, 78.9% of patients experienced the non-inflammatory endothrix form of infection and 87.6% of patients presented with occipital scalp involvement [37]. Kerion is the most severe presentation of inflammatory-type TC and is believed to be more common in rural populations due to increased contact with animals [52].…”

“…Since TC infection is uncommon in adults, there are no widely accepted treatment guidelines. Rather, the same medications used for TC infection among children are recommended for adults at varying doses, including griseofulvin, and terbinafine, and less commonly, itraconazole and fluconazole [34,37,52,[73][74][75][76][77][78][79][80]. Regardless of the selected therapy, it is recommended to re-evaluate patients approximately one month after treatment initiation to assess for improvement [72].…”

“…In a retrospective cohort study of 111 adult patients with T. tonsurans TC confirmed by fungal culture or PCR, 95 patients received 250 mg/day of terbinafine for an average of 7.2 weeks. Of these, 83.2% (n = 79) of patients achieved clinical cure, while 16.8% (n = 16) were considered to have failed treatment [37]. In a sub-analysis among patients who failed treatment vs. those who were clinically cured, patients who failed treatment were more likely to also have tinea corporis (50% vs. 20.3%, OR 3.9, 95% CI 1.3-12.1, p < 0.02).…”