Red patches on the knees. What's going on?

Red plaque on the knee may be caused by a variety of reasons, such as skin inflammation, infection, vascular disease, autoimmune disease, trauma or injury, etc., it is recommended to seek medical attention in time, after a clear diagnosis for treatment. Red plaque on the knee may be caused by a variety of reasons, the following are some common conditions: 1. Skin inflammation: Such as contact dermatitis, eczema, psoriasis, etc., these diseases may lead to skin redness, plaques and itching.2.Infections: Bacterial, viral or fungal infections may cause skin inflammation and plaques, such as furuncle, carbuncle, herpes zoster, etc.3.Vascular diseases: Vascular problems such as vasculitis and purpura may also cause red plaques in the knees.4.Autoimmune diseases: For example, autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis can affect all parts of the body, including the knees, resulting in skin damage. 5. Trauma or injury: Trauma, fall or collision at the knee may cause congestion and erythema. 6. Other causes: Drug allergies, blood diseases, metabolic disorders, etc. may also cause skin abnormalities. If red patches on the knee are accompanied by pain, swelling, fever, itching, or other discomfort, or if the patches persist or worsen, it is recommended to seek medical attention. The doctor will perform a detailed physical examination, ask about medical history, and may perform laboratory tests or other imaging tests to determine the specific cause and determine the appropriate treatment plan. Red patches on the knees may be of particular concern to certain groups of people, such as older people, people with weakened immune systems, people taking medications, or people with other health problems. These groups may be more prone to serious underlying diseases or complications. In short, red patches on the knees need to be taken seriously and it is important to seek medical attention for accurate diagnosis and treatment. Doctors can provide personalized advice and treatment options based on specific circumstances.