Amyloidosis is a group of diseases that have in common extracellular deposition of insoluble proteins in tissues and organs which results in dysfunction of that organ. The organs which are most commonly affected are liver, kidney, heart and skin.
In lichen amyloidosis, there is an abnormal deposition of amyloid material in the skin. This produces chronic itchy rash on skin surface. The lesions usually appear in lower leg, particularly over the shin. In few instances Lichen amyloidosis can also appear on thighs, forearm and on back.
The condition is usually accompanied with other skin conditions such as atopic dermatitis, lichen planus, and fungus infection.Lichen amyloidosis is more common in males. The condition is common in people over 50 years.
Causes And Symptoms Of Lichen Amyloidosis
The exact etiological factor is not known for development of lichen amyloidosis. Medical practitioners and scientists suggest that there is a preponderance of genetic inheritance. Environmental factors cannot be ruled out.
People of certain origin, especially of south East Asia and South America are more prone to lichen amyloidosis.
Lichen amyloidosis is also known to occur in people who constantly scratch or there is constant friction to their skin. Due to constant scratching, the epidermis is damaged.Below the epidermis there is a layer of dermis. Extracellular protein gets deposited on the upper layer of dermis, called papillary dermis.
The condition is common in winter and in summer when the skin becomes dry.
Lichen Amyloidosis Symptoms
Lichen amyloidosis is an intense itchy condition. There are hyper pigmented and hyperkeratotic skin rash predominantly seen on shin of lower legs. They are often present in other body parts such as arms, upper back area and on thighs. The papular (raised) lesions of lichen amyloidosis are waxy. They may combine to form thick plaques red or brown in color.
It is a localized skin condition in most cases and there is very rare systemic affection involved. The onset of this disease is normally after the age of forty; however it can be seen sometimes in young adults.
Treatment For Lichen Amyloidosis
Diagnosis and investigation: When lichen amyloidosis is suspected, the physician usually recommends histological investigation. A biopsy of skin is taken. It is then sent for histological examination. Histological findings may suggest deposition of amyloid material on the papillary dermis, the lower layer of skin. Immunofluorescence test may show IgM and IgA positive.
Treatment of lichen amyloid has largely remained unsatisfactory. It is very difficult to resolve an amyloid deposit on the skin. Most often the treatment is aimed at reducing intense itching.
- Hydro-colloid dressing is considered as first line of treatment. It is known to reduce intense itching of lichen amyloid. The size of raised lesions also gets reduced. Hydro-colloid dressings are comparatively cheap and they are easily applied. They are also beneficial in other skin diseases like psoriasis.
- Corticosteroid creams, photo therapy and dermabrasion are other modes of treatment found useful in treating the symptom of lichen amyloidosis.
- Pulsed dye laser has satisfactory improvement in itching as well as size of papules.
- Excision of individual lesion has temporary improvement, but recurrence is common.
- Antihistamines are beneficial in reducing extreme itching sensation. But they cannot be used for a long period.