Lichen amyloidosis is the most common form of primary localized cutaneous amyloidosis.
The cause is unknown, but the condition is thought to be induced by scratching. The condition is more common in men and in people with darker skin phototypes. Although it is usually an isolated finding, this condition can be associated with multiple endocrine neoplasia.
Lichen amyloidosis typically presents as multiple pruritic, firm, hyperpigmented, hyperkeratotic papules on the shins that later coalesce to give the appearance of a rippled pattern. Over time, the papules can form thickened plaques that resist treatment.
The diagnosis can usually be made clinically, particularly in patients with the classic presentation. A skin biopsy should be reserved for evolving lesions.
Lichen amyloidosis is a chronic condition without potential for malignant transformation. Treatment is not required but can be employed for symptomatic or cosmetic complaints. Therapeutic options are limited, but success has been reported with :
- Topical or intralesional steroids
- Ultraviolet light therapy
- Laser therapy
- Retinoid agents