[Self-inflicted lesions in the context of hidradenitis suppurativa: Pathomimicry]

Factitious disorders constitute a complex pathology for the dermatologist. Although a diagnosis is often indicated, it is difficult to confirm and treatment is complicated. Dermatitis artefacta is the somatic expression of an often serious psychiatric disorder consciously created by patients on their own cutaneous-mucosal surfaces but the motivation is unconscious and no secondary benefits are sought (in contrast to simulation). Pathomimicry represent a specific entity: the provocation of outbreaks of a known disease, triggered by voluntary exposure to a causative agent. Herein we report on a case of pathomimicry in a context of hidradenitis suppurativa.

A teenage girl whose main previous medical history consisted of grade-2 obesity and an episode of pubic abscess was seen at our clinic for axillary lesions. She presented in a state of negligence, was suspicious and aggressive, and refused to undress. After gaining her trust, clinical examination revealed prominent ulcerations (each with a granulated base) at a distance from the folds in the axillary areas, as well as typical hidradenitis lesions of Hurley Grade 2 with purulent openings and rope-like scars from the inguinal folds. Hospitalization was recommended and a positive outcome was achieved under antibiotic therapy with doxycycline, topical alginate and hydrocellular dressings. A psychiatric evaluation concluded that the patient was presenting dysmorphophobic narcissistic weakness, probably in reaction to recurrent harassment at school since childhood. Once she developed trust with us, which was difficult to establish, the patient admitted to having caused the lesions herself. Given the history and clinical data, as well as the negative laboratory tests, a diagnosis of pathomimicry was made.

Several cases of dermatological pathomimicry (sustainment by the patient of an ulcer with a known cause, contact with an allergen found in eczema, or renewed use of a medication implicated in toxiderma) or systemic disease (insulin injection in a diabetic patient) have been reported. To the best of our knowledge, this is the first description of pathomimicry associated with hidradenitis suppurativa. Regarding therapy, aftercare should be multidisciplinary. Confessions should not be forced and confrontations, which risk serious psychiatric collapse, should be avoided. A reassuring attitude enables psychiatry to be applied once trust has been sustainably established, hence the crucial role of the dermatologist.