Use of antipsychotic drugs in dermatology.

Antipsychotic drugs can be beneficial in dermatology because of their both central nervous system and peripheral effects. All antipsychotic drugs have a central postsynaptic dopamine D2 receptor blocking effect, which underlies their antipsychotic action. The antipsychotic drugs have varying degrees of histamine H1-receptor, cholinergic muscarinic receptor, and α1-adrenergic receptor blocking effects, which can affect cutaneous perception and the autonomic reactivity of the skin and can be potentially beneficial in the management of certain histamine or sympathetically mediated dermatologic manifestations (eg, urticaria, pruritus, hyperhidrosis). In addition to their antipsychotic effect, antipsychotic drugs also have a general anxiolytic effect related in part to their α1-adrenergic receptor blocking action, which can be of benefit in many dermatologic conditions, including pruritus. The antipsychotic drugs are most commonly used in dermatology for the management of a delusional disorder, somatic type, manifesting as delusional infestation, and as monotherapy or as augmentation therapy of selective serotonin reuptake inhibitor (SSRI) antidepressants, and for management of trichotillomania and skin-picking or excoriation disorder. There is earlier literature (1) on the possible beneficial effect of the phenothiazine antipsychotics in a wide range of pruritic dermatoses, and (2) the efficacy of pimozide as adjunctive therapy for metastatic melanoma, which both warrant further investigation.