Key points of differential diagnosis
The main difference between pyogenic granuloma and condyloma acuminatum is that the former is mostly single, with short rod-shaped lesions and smooth surface, and the lesions do not obviously continue to increase with the extension of the course of disease. Acetic acid test is negative, HPV test is negative, and histopathology shows that a considerable number of spherical masses formed by new capillaries are embedded in the subcutaneous matrix. Most of the latter are multiple, and the damage is cauliflower-like. With the extension of the course of disease, the damage increases rapidly, and the acetic acid test is positive, the HPV test is positive, and the histopathology shows diagnostic hollow cells.
What is actinic granuloma?
This disease was put forward by 1975 O'Brien. He thinks it is a chronic granuloma caused by frequent exposure to sunlight. It is common in tropical or subtropical regions, and 5 cases have been reported in China. Farmers above middle age are more likely to get sick in summer. There is no gender difference.
Etiology and pathogenesis:
This disease may be related to the cellular immune response of a weak antigenic determinant on the degenerated elastic fibers changed by photochemistry.
Clinical manifestations:
Single or clustered small papules or nodules appear on the skin irradiated by sunlight, which are normal skin color, reddish or dark red, and gradually expand and increase to form patches. The central depression is annular or not shaped, with smooth edges, pearl-like color and dike-like uplift. The diameter of the rings is 0.5-4 cm or more, ranging from 3-5 to dozens. The rings are tough, slightly infiltrated, with no scales or angulation on the surface. The skin in the rings is normal in appearance or slightly atrophied. The rings can fuse with each other, but there is no ulcer. It is common in forehead, neck, chest, upper limbs or back. After a chronic period, from months to years. People over middle age are more common, and those who often work outdoors are prone to develop symptoms or increase drama. Most of them have no conscious symptoms, or they have mild itching. It can be relieved naturally.
Pathological changes:
It is mainly elastic fibrolytic granuloma, that is, the elastic fibers in the lesion infiltration area disappear and are swallowed by macrophages. The epidermis of the initial rash is normal, and the epidermis of the old rash is atrophied. THEre are a large number of elastic fibers in the dermis around the annular rash, which are degenerated, thickened and curled, and he staining is blue (normal elastic protein and collagen fibers are dyed red). There is elastic fiber phenomenon of phagocytosis and degeneration of foreign body giant cells in the bulge of annular rash. There are smaller giant cells, histiocytes, plasma cells and lymphocytes among the large giant cells of foreign bodies. There are a few isolated denatured elastic fibers in the middle of the rash. There were no obvious changes in skin adnexa and subcutaneous tissue.
Diagnosis and differential diagnosis:
According to the annular damage of uneven skin, healthy skin color, reddish or dark red dike uplift, it is easy to occur in the face and neck, easy to see in summer, and can be confirmed by long-term sun exposure and pathological changes.
This disease should be differentiated from the following skin diseases:
(1) The clinical manifestations of granuloma annularis are similar, but the pathological changes are different. There is collagen degeneration in the middle dermis, and giant cells are rare.