Dermatitis artefacta

Dermatitis artefacta (Fig. 1) should be suspected from the presence of lesions with bizarre shapes (often linear or angular and in accessible sites) that do not conform to natural disease. The lesions are often ulcerated or crusted and do not heal as expected, although they do heal if occluded. Blisters or bruises are also sometimes found.

Fig. 1 Dermatitis artefacta: a linear lesion.

The condition tends to occur in young women. Confrontation is not recommended, as this may lead to an angry denial. Management is aimed at excluding genuine disease, establishing a rapport with the patient and gently trying to investigate the presence of psychological stresses, e.g. in the home or work environment or in social or sexual relationships.

Delusions of body image

Patients may present with no objective skin disease but still complain of symptoms such as burning or redness of the face, or display a preoccupation with an imagined problem such as excessive facial hair. This condition, sometimes known as dysmorphophobia, is usually seen in women, although it does occur in men, who may complain of a burning scrotum. Most of these patients are depressed, although some may show signs of schizophrenia. Psychiatric referral is needed for those with true delusions.

Delusions of parasitosis

Patients with this condition are convinced that their skin is infested with parasites, and they often bring collections of keratin and debris to support their contention. Self-induced excoriation of the skin may be seen. It mainly occurs in women over the age of 40 years. Most patients do not have an organic psychosis, but they are often obsessional and do have a monosymptomatic hypochondriacal psychosis. Treatment is difficult. It is necessary to exclude a true parasitosis. The antipsychotic drugs pimozide, risperidone or olanzapine may be helpful but all have significant potential side-effects that require monitoring.

Trichotillomania

Rubbing, pulling and twisting the hair is not uncommon in children and results in thinning of scalp hair, which recovers spontaneously. When the condition occurs in adults, the hair may be cut using scissors or a razor, and the prognosis is not so good.

Neurogenic excoriations

Accessible areas of the skin, particularly the forearms and back of the neck, are commonly involved in this condition, with excoriated lesions in a variety of stages of evolution from ulcers to healed scars (Fig. 2). The damage is inflicted as a result of an uncontrollable itch, but there is no primary lesion. Effective occlusion will allow healing. Acné excoriée is a variant seen in young women who squeeze and pick their acne lesions, resulting in artefactual erosions.

Fig. 2 Neurogenic excoriations on the arm.

Some have healed to leave hypopigmented scars.