Background Dapsone is an antileprotic whose mechanism of action for linear IgA dermatosis is not yet known.

Purpose To evaluate the efficacy and safety of dapsone in the treatment of linear IgA dermatosis in a paediatric patient.

Materials and methods Review of the clinical history, consultation of the outpatients dispensing software (Dipex) at the Pharmacy Unit, as well as the electronic laboratory records (Izasa). Drug efficacy was assessed by the clinical evolution of dermatological manifestations, while safety was evaluated by monitoring liver function, haemoglobin (Hb) and adverse reactions listed in the drug’s SPC.

Results The study subject was a 2 year-old patient who presented disseminated bullous eruptions over the perigenital area, accompanied by intense itching. Initial treatment consisted in high-potency corticosteroid and topical fusidic acid, in addition to recommending a gluten free diet for suspected diagnosis of linear IgA dermatosis, later confirmed by a direct immunofluorescence study. After only slight improvement of the lesions, it was decided to start treatment with dapsone 25 mg/day, following the SPC recommendations not to exceed 2 mg/kg/day. A dramatic response was observed, together with regular values in blood tests. The only adverse effect experienced was nausea. Due to a decrease in Hb values, after 4 months of treatment, the pattern of administration was spaced to alternate days, maintaining good control of the disease, although occasional diarrhoea was reported. Liver and hematologic functions remained within normal limits in the regular checks. Because of flare-ups, the dose was eventually increased to 25 mg/day, then decreased again after remission of the episode to 25 mg every third day, a pattern that continues at present, 4 years after starting treatment.

Conclusions Dapsone achieves good control of linear IgA dermatosis in our paediatric patient, but continual revisions of the dose are required. Although gastrointestinal adverse reactions and occasional decreases in Hb levels have been observed, it can be concluded that the drug’s long-term safety profile is acceptable in this case. Further well designed studies are required in order to generalise the results obtained.

No conflict of interest.