What symptom is there a red dot on the leg?

From your simple description, it may be caused by allergies and need to go to the hospital for treatment. Allergic diseases can occur in all ages from newborns to the elderly, and often have obvious genetic tendency. In allergic diseases, immediate allergic reaction is more common, and its main types are skin allergic reaction, respiratory allergic reaction, digestive tract allergic reaction and anaphylactic shock. Common diseases are as follows.

Allergic dermatitis

(1) Drug eruption: Some drugs can cause skin allergic reactions, mainly manifested as erythema, purpura, blisters and loose epidermis, itching and pain, and sometimes accompanied by low fever. There was no pigmentation after the rash subsided.

(2) Contact dermatitis: refers to skin contact with certain substances (such as jewelry, bracelets, sandals, cosmetics, etc.). ), leading to local erythema, edema, itching and pain, severe blisters, peeling and other phenomena.

(3) Eczema: erythema, papules, blisters, erosion, exudation, scabbing, desquamation and pigmentation can be seen locally or all over the body; Severe itching; There is obvious exudation.

(4) Urticaria (wheal, rash): sudden severe itching or burning sensation on the skin; Localized lumpy puffy air masses of different sizes, as small as rice grains and as large as palms, are often fingernail-to-coin-sized, slightly higher than the surrounding skin. (5) Dermatoglyphic itching: the scar after scratching by hand.

(6) Food allergy: Milk, flour, corn, eggs, sugar, tomatoes, potatoes, chocolate, fruits, beef, pork and other foods may cause allergies. The manifestations of food allergy can be varied, with rash being the most common, erythema around the face, mouth and trunk being more common, itching and desquamation, pigmentation, nausea and diarrhea. (7) Allergy caused by environmental factors: pollen, mold, dust, trees, tobacco, smoke, perfume, gasoline, paint, pesticides, detergents, drugs, pets, carpets, etc. Can cause allergies.