What causes red patches on the skin of the lower leg?

Generally, red patches on the skin of the lower leg may be caused by external friction, dry skin, allergic purpura, eczema, folliculitis, or other reasons. It is important to seek medical attention promptly and follow medical advice for treatment. Details are as follows:

1. External Friction: When the skin of the lower leg is subjected to external friction, it may cause soft tissue damage, leading to local capillary rupture, bleeding, or inflammatory reactions, thereby forming red patches, often accompanied by localized swelling and pain. Apply a cold compress using a towel-wrapped ice pack to the affected area for 5-10 minutes to promote vasoconstriction and relieve pain and swelling.

2. Dry Skin: Dry skin may lead to impaired skin barrier function, making the skin more susceptible to external irritation and infection, which can result in red patches accompanied by itching. Moisturizers or vitamin E lotion can be applied to the lower legs to keep the skin hydrated.

3. Allergic Purpura: Allergic purpura is a Type I hypersensitivity reaction triggered by allergens such as food or medications, causing increased capillary fragility and permeability, leading to red blood cell extravasation. This results in red patches on the lower leg skin, often accompanied by abdominal pain. Treatment may follow medical advice to use medications such as cetirizine hydrochloride tablets, ibuprofen tablets, loratadine tablets, etc., which have anti-inflammatory and antiallergic effects.

3. Eczema: Eczema is an inflammatory skin condition that may be related to various factors such as allergies and humid environments. It can trigger immune responses in the skin, causing symptoms such as red papules and red patches, often accompanied by itching. Under medical guidance, medications such as calamine lotion, mometasone furoate cream, or hydrocortisone butyrate cream can be used for their soothing, antipruritic, and anti-inflammatory effects.

4. Folliculitis: Folliculitis is an inflammatory reaction of the hair follicles, primarily caused by bacterial infections such as Staphylococcus aureus. It leads to inflammation of the hair follicles, causing symptoms such as itching, pain, and red patches, often accompanied by pustules. Under medical guidance, topical medications such as mupirocin ointment, erythromycin ointment, or amoxicillin capsules can be used for their anti-inflammatory and antibacterial effects.

Maintaining good personal hygiene habits, avoiding contact with allergens, and maintaining a healthy lifestyle can help prevent the occurrence of related skin diseases.