Granuloma annulare

Introduction Granuloma annulare is a benign inflammatory skin lesion of unknown etiology that occurs in the dermis or subcutaneous tissue and is characterized by ring-shaped papules or nodular lesions.

Cause

The cause is unknown and may be related to trauma, insect bites, sun exposure, oppression, drugs, viral infections, etc. Some people have detected anti-thyroid antibodies from the blood of patients with disseminated ring granulomatosis, and others have used immunological methods such as direct immunofluorescence and macrophage inhibition tests to suggest that delayed allergic reactions occur in the pathogenesis. Important role, but the nature of the antigen is still unclear; some people have detected the deposition of IgM and C3 at the junction of blood vessel wall and epidermal dermis with fluorescent antibody, indicating that the disease is related to vasculitis. Extensive research has been conducted on the relationship between ring granuloma and diabetes, with 21% of disseminated ring granulomas and 10% of patients with localized ring granulomas having diabetes, and some with insulin-dependent diabetes. The detection rate of HLA-B8 was increased in patients with localized annular granuloma, and HLA-A31 and B35 were elevated in some patients with annular granulomatosis.

an examination

Related inspection

Skin elasticity check physical examination of skin color skin disease

Children and young people are more ill, and women are 2 to 3 times more likely than men. The predilection site is the extension of the distal end of the extremities. The back of the hand and the forearm are particularly common. Except for the mucosa, any part can be affected. Typical skin lesions begin with a small, smooth, hard papule that can be normal skin tone, reddish or purple, gradually regressing at the center of the lesion, surrounded by a ring, a sinuous or arched shape, with a diameter of 1 cm to 5 cm, sometimes more Large, one or a few; no conscious performance, sometimes mild itching. The disease is generally self-limiting, most of which are naturally absorbed within 2 years, and some can last up to 25 years. The recurrence rate of this disease is high, 40% of patients relapse in the same place, but the recurring skin lesions subsided faster.

Differential diagnosis

Because of the many clinical types of ring granulomas, it is necessary to determine the diagnosis in combination with pathology. The disease should be differentiated from progressive lipid necrosis, sarcoidosis, body lice, lichen planus, persistent erythema, and infectious soft palate. Special clinical types:

1) Giant ring granuloma: single hair, deep infiltration, persistent erythema or ring lichen planus.

2) subcutaneous nodular ring granuloma: occurs in the lower limbs and buttocks, more common in children, deep infiltration, purple or reddish subcutaneous nodules, but ulcers can occur in the center of the nodules.

3) penetrating annular granuloma: occurs in the back of the hand and limbs. The central part of the lesion is usually umbilical, which is like infectious soft palate-like skin lesions. It is related to the season and can be aggravated in summer.

4) disseminated ring granuloma: occurs in the wrist, forearm, and sometimes can be spread throughout the body, but does not involve the scalp and palmar, more than 1mm ~ 2mm size, skin color, round papules, can exist in isolation or Blended into pieces. Children and young people are more ill, and women are 2 to 3 times more likely than men. The predilection site is the extension of the distal end of the extremities. The back of the hand and the forearm are particularly common. Except for the mucosa, any part can be affected. Typical skin lesions begin with a small, smooth, hard papule that can be normal skin tone, reddish or purple, gradually regressing at the center of the lesion, surrounded by a ring, a sinuous or arched shape, with a diameter of 1 cm to 5 cm, sometimes more Large, one or a few; no conscious performance, sometimes mild itching. The disease is generally self-limiting, most of which are naturally absorbed within 2 years, and some can last up to 25 years. The recurrence rate of this disease is high, 40% of patients relapse in the same place, but the recurring skin lesions subsided faster.

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