Successful treatment of recalcitrant dyshidrotic eczema with dupilumab in a child

Dyshidrotic eczema (DE) is a cutaneous reaction characterized by acute eruption of pruritic vesicles on the palms and soles. In severe cases vesicles may coalesce to form blisters, and secondary complications (e.g. painful erosions and rhagades) may also compromise the patients’ daily life. Dyshidrotic eczema is thought to be a variant of atopic dermatitis (AD) in most cases [1]. However, DE may also occur as a manifestation of allergic contact dermatitis or as a hyperergic reaction to dermatomycosis. The exact prevalence of DE is unknown, but probably accounts for up to 20 % of all cases of hand and foot eczema [1]. Dyshidrotic eczema typically affects young adults, but may also be seen in children [1]. Besides avoidance of aggravating factors and use of emollients, topical corticosteroids and phototherapy are still the mainstay of management of atopic DE, but the individual response is often limited [2, 3]. As not all patients achieve stable improvement or complete remission with these treatments, systemic therapy may be indicated – especially in very severe or chronic cases. Besides corticosteroid pulse therapy, immunosuppressive approaches with cyclosporine A (CyA), azathioprine or methotrexate (MTX) have been reported, mostly in adults [1, 2]. We describe the case of a 12-year-old boy with recalcitrant dyshidrotic eczema (DE) successfully treated with the human monoclonal antibody dupilumab. To the best of our knowledge this is the first pediatric case showing efficacy of dupilumab in the treatment of DE. The boy presented to our outpatient clinic with a 6-month history of painful vesicular eczema of the hands and feet. Before admission, he was treated with topical and systemic antimicrobials as well as UVA and topical corticosteroids (prednicarbate) without effect. Besides AD in early childhood there was no history of allergic rhinoconjunctivitis, asthma or other diseases. There was no evidence of contact allergy. Previous histopathology showed intraepidermal vesicles, epidermal spongiosis, parakeratosis and orthokeratosis as well as a mixed-cell perivascular dermal infiltrate, compatible with DE. Routine laboratory investigations revealed a slightly elevated level of total IgE (147 IU/ml), but no further pathology or signs of infection (swab, culture). Massive vesiculation with pruritus and painful erosions led to four in-patient treatments (> 35 days) with repeated school absences (> 75 days) and social withdrawal. The boy’s school performance dropped due to massively impaired concentration, manual skills (writing) and mobility, and finally he did not pass his grade. On examination, the palms and soles showed crops of clear to yellowish vesicles and bullae on an erythematous ground (Figure 1a, b). The rest of the skin was normal. With daily application of potent corticosteroids (mometasone furoate) extensive blistering continued. Transient remission was achieved with oral pulses of prednisolone (1 mg/kg bw) but tapering down prednisolone led to new exacerbations well above the individual Cushing threshold dose, even after introduction of MTX (10 mg/m2, s.c. weekly over three months). A switch to CyA (5 mg/kg bw p.o.) was made. Against our expectations, Clinical Letter