Primary cutaneous amyloidosis

Introduction to primary skin amyloidosis Primary collagenous amyloidosis (also known as lichenoed and macular amyloidosis); a type of amyloidosis (an1yfoidosis), which refers to the deposition of amyloid in normal skin tissue. A chronic skin disease that does not involve other organs. Primary skin amyloidosis is caused by the deposition of amyloid material on the skin. Amyloid is a globulin and mucopolysaccharide complex, named for its chemical reaction like starch, such as iodine, but it has nothing to do with starch. It has been suggested that this disease is autosomal dominant, and in some cases, blood lipids and proteins are abnormal, so it is considered to be related to metabolic disorders. Some patients have a family history. More men than women, more common in young adults, can be extended for years or decades. basic knowledge The proportion of illness: 0.002% Susceptible people: no special people Mode of infection: non-infectious Complications: pruritus

Primary skin amyloidosis etiology

The etiology is still unknown, and may be related to heredity and immunity. Studies in light microscopy, electron microscopy histochemistry and immunology have confirmed that amyloid substances are derived from the epidermis, and the denatured epidermal cells escape into the dermis and are converted into amyloid. Deposited in the dermal papilla.

Primary skin amyloidosis prevention

1. Pay attention to personal hygiene and keep your skin clean.

2, as clean as possible, thoroughly and thoroughly.

3, susceptible population should avoid the use of skin care products containing too much oil to prevent clogged pores.

4. Increase physical activity and improve the body's ability to resist disease.

5, try to avoid skin trauma, such as wounds, should be disinfected in time, and keep clean, try to make it dry, do not provide a warm and humid environment for pathogens.

Primary skin amyloid complication Complications pruritus

The skin lesions can be gradually extended to the flexion of the lower leg, the thigh, the ankle and the back of the foot, and even the forearm extension, the abdomen or the chest wall.

Primary skin amyloidosis symptoms Common symptoms Itching papule pigmentation itchy lichen planus scales

Mossy-like amyloidosis is the most common, and the age of onset is not limited. Typical lesions occur in the anterior chamber, showing a normal skin tone to a yellow-brown papule, about 1 to 3 mm in size, often with a few scales on the surface, and the top is often hyperkeratotic and rough. The papules are densely integrated, but often do not fuse, consciously itchy, sometimes the papules are arranged in a bead-like shape along the skin lines, which are characteristic, and can also be fused into plaques, the surface is scorpion-like, with hypertrophic lichen planus or chronic simple moss. Similar, but still recognize the papules on the surface of the plaque, brown pimples can also be seen at the edges of the plaque, and the skin lesions can gradually spread to the flexion of the calves, the thighs, the ankles and the back of the feet, and even the forearm extension , abdomen or chest wall, plaque amyloidosis is less common than mossy amyloidosis, which is characterized by the aggregation of punctate pigment spots into corrugated or reticular brown pigmentation spots, symmetrically distributed in the dorsal scapular region, calves, arms, breasts and Hip, moderate itching, easy to be misdiagnosed as post-inflammatory hyperpigmentation, sometimes mossy and plaque lesions can exist at the same time, and can change each other, called biphasic or mixed skin amyloidosis (bi Phasic amyloid osisiormixed amyloidosis), the disease is chronic, often prolonged for many years, can resolve itself, but can still relapse.

Most of the amyloid deposits in the dermal papilla, no more than the sub-papillary plexus, the mossy amyloidosis and the plaque amyloidosis are similar, the main difference between the two is the difference in epidermal changes, the former epidermal acanthosis hypertrophy and hyperkeratosis, The latter did not change, but pigment incontinence was more significant, amyloid deposition was less than the former, staining amyloid was homogeneous, mild eosinophilic mass, including fissures, fixation and dehydration, amyloid Due to shrinkage, when HE staining cannot be determined, Congo red, crystal violet or thioflavin T can be used for special staining. In the past, paraffin sections were stained with alkaline Congo red and observed under polarized light. Amyloid protein Green birefringence is the most reliable method to prove amyloid, but it is known that the same staining reaction can be seen in gelatinous measles, hyalinization of skin and mucosa, and porphyria. Fortunately, amyloidosis and the above three diseases are It can be distinguished clinically. Recently, some cotton dyes such as Tahong and Ri Scarlet No. 5 have been reported to be stained under polarized light. It is said that sensitivity is related to Congo red. But higher specificity, no affinity for glue-like proteins and protein transparent, to be further confirmed.

Examination of primary skin amyloidosis

Skin histopathological examination, combined with crystal violet, thioflavin T or Congo red special staining, if necessary, electron microscopy of amyloid fibrils with special structure, can be diagnosed.

Diagnosis and differentiation of primary skin amyloidosis

diagnosis

According to typical skin lesions, skin histopathological examination, combined with crystal violet, thioflavin T or Congo red special staining, is generally not difficult to diagnose; if necessary, electron microscopy of amyloid fibrils with special structure can be diagnosed.

Differential diagnosis

The disease should be clinically differentiated from neurodermatitis, nodular pruritus, hypertrophic lichen planus, post-inflammatory hyperpigmentation, and histopathologically, it should be differentiated from colloidal malignant rash, clear skin and mucous membrane, and porphyria.

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