Management of Tinea Capitis in children under 10 kg : Results from a French multicentre study

Tinea capitis (TC) is a dermatophyte infection of the scalp, most common in school children aged 3 to 7 years,1 but rare in infants under 2 years old.2 Griseofulvin was the only systemic treatment approved for paediatric TC in France until its market withdrawal in 2021. Following this, the Centre of Evidence of the French Society of Dermatology developed a management algorithm for children weighing more than 10 kg.3 In addition to griseofulvin, the itraconazole oral solution was recently withdrawn from the French market, further limiting therapeutic options for children under 10 kg.4 The management of TC in children under 10 kg remains challenging and poorly defined. We conducted a retrospective multicentre nation-wide study to describe the management of microbiologically documented TC in children weighing less than 10 kg. Between December 2022 and June 2024, 26 patients were included (Figure 1a), with a mean age of 11 months (1–25 months) and a mean weight of 8 kg (range: 4–10 kg). The sex distribution was balanced (54% girls). In ¾ of cases, there was a notion of a family contact. Differentiating between microsporic and trichophytic TC based on lesion size was minimally useful; 19% of children exhibited diffuse scaling. The proportions of microscopic and trichophytic TC were equal (~50% each). The primary pathogen was Microsporum audouinii (9 cases) (Figure 1b). Anthropophilic species accounted for 75% of cases. Two of the 13 patients who received local treatment (LT) alone as the first-line therapy recovered. Most children (n = 23) received at least one systemic antifungal therapy (ST), sometimes combined with LT (n = 15) and sometimes in second-line therapy (Table 1). When ST was initiated, itraconazole was preferred for microsporic TC (n = 10/11, p < 0.001), while terbinafine was favoured for trichophytic TC (n = 10/12, p = 0.002). Itraconazole was prescribed at 3–5 mg/kg/day and terbinafine at 62.5 mg/day or 5–6 mg/kg/day. Only two children received fluconazole (5–8 mg/kg/day). Two children were lost to follow-up. Among the 24 children monitored, 21 were cured and 3 partially improved. Baseline tests were performed in 39% of cases, during treatment in 30% and post-treatment in 13%, revealing no significant abnormalities except mild hepatic cytolysis (<2 N) in one terbinafine-treated case, with no hematologic toxicity. ST was well-tolerated; only one child vomited under itraconazole, which did not recur after re-administrations. This is the first study which specifically focuses on TC in children weighing under 10 kg, aside from a meta-analysis by Song et al.2 and small case series.5, 6 Most of the studies involved treatment with griseofulvin, which no longer addresses current therapeutic challenges. Anthropophilic species were predominant, including M. audouinii, a fungus quite contagious from patient to patient, transmitted via fomites. It was easily eradicated by griseofulvin and it is unfortunate that this drug is no longer available. Some authors suggested that LT alone could be effective in newborns.7 In our study, LT alone served as a reasonable interim measure while awaiting microbiological results, but was not sufficient for curative treatment. Clinicians appear to be extending the treatment recommendations for children over 10 kg to those under 10 kg. Terbinafine (during meals) for trichophytic TC and itraconazole (fasting) for microsporic TC showed good clinical efficacy. The clinical and biological safety, particularly haematological and hepatic, which had been feared, was good, as observed in older children.8 When there were no paediatric formulations for infants, tablets were cut and crushed, or preparations were made, resulting in treatment delays and potential contamination. This study provides valuable clinical and microbiological data on TC in children weighing under 10 kg and supports the extension of treatment recommendations to this population, where scientific data and consensus are lacking.9 None. None declared. Reviewed and approved by the Assistance Publique des Hôpitaux de Marseille the 10 November, 2022 and registered PADS 22–377. This research is exempt from ethical review. The patient's legal representatives have given their written informed consent for the use of the photographs. The data that support the findings of this study are available from the corresponding author upon reasonable request.