Papular dermatitis

This situation often happens in our daily life. Some mosquitoes like to surround you. I don’t know if it’s because of your blood type, but sometimes they will bite you when you are not paying attention. After a while, you will find that one or several cakes have appeared at the place where you were bitten. If you are lucky, the cakes will disappear automatically after a few hours; but if you are unlucky, if those mosquitoes have viruses, more cakes will appear.

In fact, human skin is very fragile. Not only is it often damaged by wind, rain and sun, but it is also often visited by mosquitoes in hot weather. Many times, it is not these reasons that cause skin discomfort, such as papular dermatitis. So, let’s talk about the disease of papular dermatitis in detail.

A papule is a localized, raised, substantial lesion on the skin surface. The papule-like lesions can be seen by visual examination and felt by palpation. They are generally small in size and usually less than 1 cm in diameter. If the papules enlarge or merge into flat, raised, and flaky forms, they are called plaques. Papules are mostly round, quasi-round, polygonal or irregular in shape. The top of the papule can be pointed like a cone, round like a hemisphere, flat, or concave in the middle like a umbilicus. The color can be red such as psoriasis, purple such as lichen planus, yellow (xanthomas), white (atrophic sclerotic lichen), brown (pigmentation), etc. Papules can occur in various parts of the body or in the areas of hair follicles and sweat glands. They may exist for a short or long time, may be numerous or few, may be soft or hard, have a smooth or rough surface, may be papillary or covered with scales, may be scattered or clustered, may be localized or systemic, or may be symmetrical. The severity of subjective symptoms varies, such as itching or no subjective symptoms. If the lesion is between papule and macule with a flat and slightly raised surface, it is called maculopapular. If there are blisters or pus scars on the top of the papules, it is called papule scar rash or pustular papules.

Causes of papules

Various skin diseases can present as papules. Some cases only present with papules, while others are accompanied by other skin lesions. The lesions of papules are located in the epidermis or upper dermis. Therefore, from a pathological point of view, the mechanism causing papules is the accumulation of certain metabolic products in this area; or localized proliferation of epidermal or dermal cells; or inflammatory edema and infiltration of various cells in this area can all manifest as papules.

Deposition of metabolic products: For example, the papules of skin amyloidosis are caused by the deposition of amyloid protein in the dermal papillae. The papules with new fluid-like edema and lichenification are caused by the deposition of large amounts of alkaline protein in the upper dermis.

The papules of colloid miliary papules are caused by infiltration of homogeneous colloid masses in the papillary dermis.

Papules caused by localized proliferation of epidermal or dermal cells, such as common warts, flat warts, and psoriasis, are all caused by excessive proliferation of epidermal cells resulting in localized protrusions of the epidermis. German and dermatofibromas are also papules formed by proliferating cells.

Papules caused by localized edema of the epidermis are seen in eczema, contact dermatitis, etc. The papules caused by various cells infiltrating the epidermis or dermis have their own clinical characteristics. Purulent inflammatory papules are mainly infiltrated by neutrophils; chronic inflammatory papules are mainly infiltrated by lymphocytes; papules caused by allergic factors are mainly infiltrated by eosinophils; tuberculous papules are infiltrated by epithelioid cells and lymphocytes; syphilitic papules are infiltrated by plasma cells; and xanthomatosis is characterized by foam cell infiltration. The pathogenesis of papules is related to its pathogenic factors.

In fact, papular dermatitis is just a common skin disease in humans. In reality, many people also develop papular dermatitis due to food allergies. When someone accidentally gets papular dermatitis for some known or unknown reasons, he or she should go to the hospital for examination and treatment as soon as possible. Only with timely treatment can you recover your health as soon as possible.