Why do big lumps appear when I scratch my body?

Diseases can appear in people's bodies due to many factors in daily life, and among the many diseases, the most troublesome is allergy. Many people suffer from this condition due to their physical constitution, and some people get big bumps on their bodies when they scratch. Many people don't know the reason for this condition. So, why do big lumps appear when you scratch your body?

First, why do big bumps appear on your body when you scratch it? The causes can be divided into primary irritation and allergic reaction. ① Primary irritant contact dermatitis: The contact material is very irritating to the skin, and anyone who comes into contact with it may develop dermatitis, which is called primary irritation. There are two types of primary irritants. One is very irritating and causes illness within a short period of time after contact; the other is weaker and causes illness after a longer period of contact, such as soap and organic solvents. ② Allergic contact dermatitis: The contact material is basically non-irritating. A small number of people become sensitized after being exposed to the substance. If they come into contact with the substance again, dermatitis will occur at the contact site and its vicinity after 12 to 48 hours.

Second, the symptoms of dermatitis are generally non-specific. Due to different contact objects, contact methods and individual reactions, the form, scope and severity of dermatitis are also different. In mild cases, local erythema appears, ranging from light red to bright red, with slight edema, or dense needle-sized papules. In severe cases, erythema and swelling are obvious, and there are many papules and blisters on this basis. Bullae may occur when the inflammation is severe. When blisters rupture, there will be erosion, exudation and crusting. If it is a severe primary irritation, it can cause epidermal necrosis and shedding, and even cause ulcers deep into the dermis. When dermatitis occurs in areas with loose tissue, such as eyelids, lips, foreskin, scrotum, etc., there will be obvious swelling, localized edema without clear edges, shiny skin, and disappearance of surface texture. The location and range of dermatitis are consistent with the contact site of the contact object, and the boundaries are very clear. However, if the contact object is gas or dust, the dermatitis is diffuse without definite clear boundaries, but it mostly occurs in exposed parts of the body. Most subjective symptoms include itching and burning or distending pain. In a few severe cases, there may be systemic reactions such as fever, chills, headache, nausea, etc. The course of the disease is self-limited. Generally, after the cause is eliminated and treated properly, it can be cured in 1 to 2 weeks. Repeated contact or improper handling may turn into subacute or chronic dermatitis, presenting as reddish-brown lichenoid or eczematous changes.

Why do big bumps appear on your body when you scratch it? Carefully inquire about the environment related to the onset of the disease, the type, quantity, physical and chemical properties of the substances contacted, the length of contact time, the method of contact, whether there have been similar rashes in the past, etc. Analyze which substances may be related from the medical history to provide a basis for skin patch testing. Once the cause of the allergy is found, try to avoid further exposure. Irritants or toxic substances remaining on the skin should be rinsed off as quickly as possible. Clean water, saline or light soapy water can be used for rinsing. If the contact object is a strong acid, it can be rinsed with a weak alkaline liquid (such as soda water); if it is a strong alkaline substance, it can be rinsed with a weak acidic liquid (such as boric acid solution). 2. To avoid irritation that may cause clinical symptoms, local irritation should be minimized. Avoid scratching, do not wash with hot water, and avoid strong sunlight or hot air stimulation. 3. Systemic treatment: oral antihistamines, such as cyproheptadine, diphenhydramine, chlorpheniramine, acrivastine, cetirizine, mizolastine, ebastine, desloratadine, etc.; large doses of vitamin C taken orally or intravenously; 10% calcium gluconate injection, intravenous push. If the area is extensive and the erosion and exudation are severe, glucocorticoids can be given. Such as oral prednisone, triamcinolone or dexamethasone; intramuscular injection of Diprosone. For severe cases, hydrocortisone or dexamethasone can be given intravenously first, and then maintained orally after the symptoms are alleviated. If contact dermatitis is accompanied by local infection, such as lymphangitis, lymphadenitis, and soft tissue inflammation, antibiotics can be used. For mild cases, erythromycin, penicillin V potassium, cephalexin, or sulfonamides can be taken orally; for severe cases, penicillin, cephalosporin, or quinolone antibiotics can be given intravenously.