Monosymptomatic hypochondriacal psychosis complicated by self-inflicted skin ulceration, skull defect and brain abscess.

Self-inflicted dermatoses are associated with personality disorders and psychoses, including monosymptomatic hypochondriacal psychosis (MHP), which is characterized by a delusion involving a particular hypochondriacal concern. We report an unusual case of MHP with severe mutilation of the skin complicated by a skull defect and brain abscess. The patient was a 66-year-old uneducated man who damaged his forehead repeatedly because he believed that a 'toxic root' in the forehead was the source of his general ailment. He admitted that the lesions were self-inflicted. There was no other evidence of psychosis or primary skin disease and MHP was diagnosed. Despite initial favourable response to pimozide, the patient was lost to follow-up for 4 years, during which he continued to damage his forehead and applied corrosive agents. He was then referred with a personality change and a 6 x 4 cm bony defect in the skull, complicated by herniation and abscess of the left frontal lobe. This case represents one of the most severe examples of self-mutilation ever reported. The differential diagnosis of dermatitis artefacta and the principles of treating MHP are discussed.