Abstract
Acquired reactive perforating collagenosis is a rare cutaneous disorder characterised by the extrusion of abnormal connective tissue trough epidermidis and/or follicular units. Reactive perforating collagenosis is often associated with systemic diseases in which pruritus is a common symptom (e.g., diabetes and chronic kidney disease). Less commonly, it has been associated with chronic inflammatory dermatoses, including atopic dermatitis, as in this case. In this report, we describe the exceptional case of a 35-year-old man affected by acquired reactive perforating collagenosis associated with atopic dermatitis who was resistant to conventional topical and systemic treatment and experienced complete resolution of clinical signs and symptoms after 12 weeks of treatment with dupilumab. In our patient, the severe pruritus induced by atopic dermatitis likely contributed to the development of acquired perforating collagenosis lesions, which are thought to be a reactive response to chronic scratching and repetitive injury to the skin. Chronic pruritus in atopic dermatitis is known to be driven by type 2 cytokines, including IL-4 and IL-13, and dupilumab, a monoclonal antibody inhibiting IL-4 and IL-13 signalling, has been shown to be effective in the treatment of moderate to severe atopic dermatitis as well as other type 2-driven pruritic dermatological conditions. This case supports the potential use of dupilumab for the treatment of reactive perforating dermatosis.