Le pou rouge du poulailler (Dermanyssus gallinae) : une cause méconnue d’urticaire

Abstract

Dermanyssus gallinae is a hematophagous ectoparasite on poultry. Accidentally, this parasite could reach human, leading to itchy cutaneous rash. In dermato-allergology or allergology, red and icthy rashes are a quite usual reason for medical consultation. We describe two cases of red itchy rashes in two patients, which made us suspect the implication of ectoparasite Dermanyssus gallinae. In both cases, the parasite has been recognized by families. The source of these parasites was a chicken coop (with an intermediary vector, possible rats) and, in the other case, a nest of birds in communication to the bedroom of the child implicated. Treatment is firstly eviction of the parasite by reducing potential sources of infestation, or vectors of Dermanyssus gallinae in contact with human environment. Symptomatic treatment of pruritus could be applied (dermocorticoids and antihistamines) but these treatments will be efficient only when the parasite eradication will be effective. When a patient is addressed with the initial suspicion of allergy in a context of red and itchy cutaneous rash, diagnosis of parasite bites must be evoked. Active research of clinical elements in favor of parasite implication is fundamental. As in all allergology medical consultations, precise collection of medical history is fundamental and differential diagnoses has to be in the mind of allergology physicians.