Primary limited cutaneous amyloidosis

Introduction to primary limited skin amyloidosis Primary localized cutaneous amyloidosis refers to amyloidosis that originates in the skin and is not affected by other systems and is not secondary to other skin diseases. basic knowledge The proportion of illness: 0.0005% Susceptible people: no special people Mode of infection: non-infectious Complications: Eczema

Primary limited skin amyloidosis

Causes:

The etiology is not clear. The rash-like and lichen-like skin amyloidosis may be related to family genetic factors. It is observed that family history has an incidence of up to 28% and has autosomal dominant genetic characteristics. In addition, natural factors in some areas are High temperature, humidity, etc. are also the cause of the disease. Long-term scratching of the skin leads to thickening of the skin, hyperkeratosis and abnormal pigmentation, forming a so-called friction melanosis, which can be followed by amyloidosis. Become sick.

Pathogenesis

The rash-type amyloidosis is closely related to the amyloidosis of the mossy skin. It often exists at the same time. The former can be developed into the latter by scratching, and the latter can be converted into the former after treatment. It is a different development stage of the same type. The formation of amyloid protein is currently considered to be a "keratin body" produced by apoptosis of epidermal keratinocytes, and its morphology is similar to that of lichen planus, which contains a tonic. Fiber, immunofluorescence examination found anti-keratin autoantibody deposition around amyloid, skin heterochromia-like amyloidosis is autosomal recessive, solar ultraviolet radiation is an important predisposing factor, of which UVB Most obvious, but there are other spectroscopy and even gamma-ray-induced reports of this disease. Nodular skin amyloidosis has obvious plasma cell clonal proliferation in amyloid mass, and its essence is actually extramedullary plasmacytoma. Locally infiltrating a large number of plasma cells to form plasma cell cachexia, secreting excess immunoglobulin and denatured into amyloid White, which also induce reactive T lymphocytes infiltration.

Primary limited skin amyloidosis prevention

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Primary limited skin amyloid complication Complications eczema

The disease has no complications.

Primary limited skin amyloidosis symptoms Common symptoms Itching skin dry itchy pigmented maculopapular rash scalp skin hypertrophy amyloid deposit

1. Spot-type and moss-like skin amyloidosis (MA) and lichenoid amyloidosis (LA) are the most common localized skin amyloidosis The two types are limited to the skin, and there is no report that the two develop into systemic amyloidosis. The rash type occurs in middle-aged women, mainly in the back scapular region, and can also involve the trunk and limbs. The rash is Brown or purple-brown pigmentation spots, which are formed by punctate pigmentation spots, which are reticular or corrugated. They have diagnostic value, rash is not itch, itch has keratotic papules and rough surface, and mossy type It is called amyloid metamorphosis, more common in middle age, both sexes can be affected, the rash is distributed symmetrically in front of the calf (Figures 1-3), followed by the outer side of the arm, waist, back and thigh, starting with a needle-sized brown spot, after Become a pointed papule and gradually increase, flat bulge, hemispherical, conical or polygonal, about 2mm in diameter, hard texture, brown, brown or similar normal skin, smooth and shiny or a little scale on the surface, keratinization Degree and roughness, black horny plug at the top, leaving umbilical depression after exfoliation, early rash scattered, can be densely integrated after the film but often do not fuse together, the surrounding edge is still visible scattered brown pimples, calf and upper back rash along the skin The pattern of rosary is characteristic, consciously itching is severe, itching can be preceded by rash for 1 to 2 months, long-term scratching can deepen the damage of the skin, or the rash merges into a flaky plaque, and some The ichthyosis-like, eczema-like or nodular pruritus-like skin lesions often have pigmentation or hypopigmentation, and the disease progresses slowly. Once the rash is difficult to resolve, it has no significant effect on general health.

2. Amyloidosis cutis dyschromica is common in men. It is divided into two types: prepubertal and adult. The rash is mainly distributed in the limbs. It develops slowly, has skin atrophy, telangiectasia, and pigmentation. Changes in skin heterochromia, such as hypopigmentation, may be accompanied by blisters and palmoplantar keratosis.

3. Nodular cutaneous amyloidosis is rare. There are two subtypes in the clinical manifestations: large nodular swelling and nodular atrophy. The former is characterized by intradermal or subcutaneous nodules, and the surface covers normal skin color or Brownish yellow skin; the surface of the nodular surface is atrophied, yellowish white, the rash can be single or multiple, the nodular tissue is very fragile, and mild trauma can easily cause blisters and/or bleeding.

Primary limited skin amyloidosis test

There may be an increase in erythrocyte sedimentation rate, abnormal globulin such as or gamma globulin. The Nomland test is to inject 1.5% Congo red solution into the skin of suspicious skin lesions. After 24 to 48 hours, only amyloid remains red. Microscopic examination of the disease positive rate of up to 80%.

Histopathology: The deposits of rash-like and mossy skin amyloidosis are confined to the dermal papilla, which are hemispherical, conical or agglomerate, varying in size, with fissures between the epidermis and HE staining. The texture may have a small amount of blue-stained cell debris components, excessive epidermal hyperplasia, irregular thickening of the granular layer and the spinous cell layer, atrophy of the epidermis above the amyloid protein, liquefaction and degeneration of the basal cells, especially prominent in the plaque. Amyloid deposits around the blood vessels of the skin-like amyloidosis, showing irregular epidermal hyperplasia, prolonged epidermal processes, sheath-like amyloid deposits around the hair follicles, epidermal atrophy of nodular skin amyloidosis Thin, epidermal exudation disappears, large amyloid deposits under the epidermis extend from the dermis to the skin, the blood vessel wall can be thickened by the deposition of amyloid substances, sweat glands, fat cells can also be affected, and chronic inflammatory cell infiltration in the dermis It is stained with methyl violet or crystal violet, and the amyloid protein can be dyed into bright purple red by heterochromatic staining; the Congo red stained polarized microscope is green and has double fold ; PAS staining, amyloid-resistant amylase-positive, immunofluorescence, immunoglobulin deposition around amyloid, has been confirmed as anti-keratin autoantibody (AK auto Ab), DACM staining The disulfide bond band shown also indicates that amyloid is derived from keratin.

Diagnosis and differentiation of primary limited skin amyloidosis

diagnosis

1. Typical rash, histopathological changes and special staining show that amyloid is the main basis for the diagnosis of this disease, and the positive Nomland test can help to confirm the diagnosis.

2. TCM syndrome differentiation

(1) Rheumatoid accumulation type:

The main card: local skin hypertrophy, the formation of localized lichen-like changes, continuous itching, thin or white tongue coating, pulse slow or slow.

Dialectical: rheumatism, skin dying.

(2) blood deficiency and dryness type:

Main card: The rash is light, rough and fat, and the face is not bright, the tongue is light, and the pulse is fine.

Dialectical: blood deficiency and dryness, skin dying.

(3) Spleen deficiency and wet stagnation type:

The main card: dry skin, a small small papule on the side of the lower extremities, densely integrated tablets, moss-like changes, consciously itchy, dry stool or diarrhea, heavy limbs, weak tongue, greasy tongue, greasy tongue, pulse slow.

Syndrome: spleen dampness, skin dystrophy.

Differential diagnosis

The disease should be differentiated from neurodermatitis, nodular pruritus, hypertrophic lichen planus, gelatinous measles, and lipoproteinosis.

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