Lichen amyloidosis is a mesenchymal dysproteinosis characterized by the deposition of amyloid exclusively in the skin. It is classified under the ICD-10 code E85.4.
Clinical variant of primary cutaneous amyloidosis involves the extracellular deposition of amyloid in the skin without signs of its deposition in internal organs. The etiopathogenesis is unknown, but familial cases of the disease have been identified. It is more common in elderly men.The eruptions are symmetrical, occurring predominantly on the anterior surfaces of the shins. They appear as multiple firm papules, 1 to 8 mm in diameter, closely packed but not coalescing, with smooth surfaces or covered with small dirty-gray scales. The papules are semi-transparent, shiny, slightly elevated, and hemispherical in shape. Their color varies from flesh-colored to light pink with a reddish-brown or bluish tinge.
The affected areas are firm and do not fold easily, with a cobblestone-like surface that shows evidence of scratching and hemorrhagic crusts. There may be verrucous lesions with marked hyperkeratosis. Intense pruritus is characteristic.
Combined cases of lichen amyloidosis and macular amyloidosis are referred to as biphasic amyloidosis because they are considered to be manifestations of the same disease.- Hypertrophic lichen planus
- Lichen myxedematosus
- Tuberculosis verrucosa cutis
- Lichen simplex chronicus
- Lipoid proteinosis
- Oral acitretin at a dose of 0.5-1 mg/kg.
- Chloroquine at a dose of 0.25 g twice a day.
- Topical glucocorticoid ointments applied under dressings.
- Anti-itch medications and ointments containing naphthalan oil or ichthammol.
- Laser therapy may be considered in cases of localized lesions.