Diagnosis: Lichen Amyloid

She had been treating her eczema with medium-potency topical steroids without improvement of the lesions. She complained of increased roughness and texture on her lower extremities.

Histology revealed an acanthotic epidermis with confluent laminated hyperkeratosis. The papillary dermis showed homogenization and accumulation of amorphous, pale pink-blue material. There was a band-like inflammatory infiltrate in the upper dermis. The amorphous material stained positive for cytokeratin by immunohistochemistry.

A diagnosis of lichen amyloid was made. The patient was started on clobetasol ointment under occlusion and narrow-band UVB treatments three times a week. She reported improvement in pruritus and lesions at 2 months.

Of the three major forms of primary cutaneous amyloidosis (macular, lichen, and nodular), lichen papular amyloid is the most common. The average age of onset is in the fifth decade. As in my patient, the most common site of presentation is the extensor surfaces such as the pretibial area in 80%-90% of patients. Other sites affected include the back, arms, thighs, and buttocks.

Pruritus is present in approximately 90% of patients, and can present months before amyloid collections become apparent. Primary cutaneous amyloidosis is seldom associated with systemic amyloid.

The pathophysiology of lichen amyloid is not completely understood, although it is strongly associated with longstanding exposure to friction of scratching. Successful treatment is targeted at reducing pruritus and chronic friction. Sedating antihistamines, topical steroids, and intralesional steroids have been used successfully. UVA and UVB phototherapy has been shown to have some benefit.

This case was first presented at Maryland Derm, at the University of Maryland School of Medicine in Baltimore, by Dr. Martin, Dr. Matthew Bremmer, and Dr. Linda Lutz.