Dermanyssus gallinaeinfestation: An unusual cause of scalp pruritus treated with permethrin shampoo

Abstract

Dermanyssus gallinae is a blood parasite of wild birds, but it is also a pest in the poultry industry. It occasionally bites mammals and thus rarely creates skin problems such as itching, papules, vesicles, and dermatitis. A 92-year-old man presented with severe itch on his head, particularly at night. He had been misdiagnosed with senile pruritus and treated with antihistamines and topical corticosteroids with temporary relief of the symptoms. On the basis of clinical and parasitological findings, D. gallinae dermatitis was diagnosed. Decontamination of the patient's immediate environment was not helpful. The patient was successfully treated using a 1% permethrin shampoo once a week for 2 weeks. During 3 months of follow-up he was free of symptoms. The case is of significance because most dermatologists have difficulty identifying ectoparasitoses, such as those that arise within new or atypical conditions.

Dermanyssus gallinae(chicken mite): an underdiagnosed environmental infestation

“…It is important to remember that avian mites are difficult to recover from the skin and the mite is usually not found, so clinical suspicion is important, and patients should be questioned about risk factors for this infestation and told how to examine their environment to detect the mite. To our knowledge, this is only the second reported case in which the mite was found alive on a patient’s body during the day 6 …”

“…We believe that D. gallinae infestation is an increasing problem, because a number of similar cases of infestation through indirect contact with birds’ nests 2,6–8 and infected pets 3,5 have been reported over the past few years. Moreover, D. gallinae may be a public‐health problem because of its potential role as a vector of disease (zoonosis).…”

“…When its regular host is not available, the mite may attack other mammals or humans as accidental hosts, displaying ‘bite and run’ behaviour, as it cannot complete its life cycle on the human body 3 . The cases documented in humans have resulted from occupational exposure, 5,6 direct contact with the bird or other infested pets, 3 proximity to infected areas (nests 4,7 and ventilation shafts 2 ) or airborne spread 1 …”

“…The patient should have a bath rather than a shower to ensure that mites are removed, and if required, symptomatic treatment with antihistamines and topical corticosteroids should be given 1 . The use of topical acaricides is controversial, because the mite does not live or reproduce on humans, but despite this, some authors recommend applying 1–5% topical permethrin 6 . Cohabitants should be treated in the same way as the patient if they are heavily infested; light infestations can usually be controlled by bathing.…”

Zoonoses in pet birds: review and perspectives

“…Such infestations are in direct relationship with dermatologic clinical syndromes in humans (“pseudo-scabies”), associated with pruritic syndrome [32-38]. Since D. gallinae has been provento shed zoonotic pathogens [28,37] and since birds like pigeons have been found to be perching alongside hospital walls [35], one could point out the eventual risks encountered by immunocompromised humans, like hospitalized people, if they experience such a situation.…”