Dupilumab-associated head and neck dermatitis (DAHND) is a paradoxical adverse reaction distinct from the underlying atopic dermatitis (AD) for which dupilumab is prescribed. It presents as erythema on the head and/or neck, occurring in patients whose AD elsewhere is typically well controlled. Notably, neither facial nor neck erythema was reported in phase 3 clinical trials; DAHND has been identified exclusively through real-world experience and has had a reported incidence of up to 10% in real-world cohorts.

DAHND affects both adults and children and typically develops weeks to months after dupilumab initiation. No clear sex or race / ethnicity predilection has been established, although cases have been reported across diverse populations worldwide. The typical presentation is sharply demarcated, patchy erythema of the face and neck, often described as a "red face," with notably less scaling than the patient's usual eczema.

Many patients remain minimally symptomatic, with little to no itch or burning despite the visible erythema, while eczema at other body sites is concurrently well controlled. Although generally well tolerated on long-term follow-up, DAHND can cause significant cosmetic distress and, in a minority of cases, can lead to dupilumab discontinuation.

The pathogenesis of DAHND is incompletely understood. A leading mechanistic explanation involves dampening of type 2 inflammation in DAHND lesions due to dupilumab, with concomitant hyperactivation of interleukin (IL)-22-associated responses. Additional postulated causes include Malassezia sensitization – elevated pretreatment serum Malassezia-specific immunoglobulin E has been prospectively associated with DAHND development – and topical corticosteroid withdrawal, as a large proportion of affected patients have a history of prolonged facial topical corticosteroid use, raising the possibility that steroid cessation plays a contributing role in some cases.