What is the cause of a large slightly itchy red rash on leg between knee and ankle that darker edges with separate little spots appear to spread from pores?

The symptoms described may indicate a skin condition called lichen simplex chronicus (LSC), also known as neurodermatitis. LSC is a chronic inflammatory skin condition characterized by one or more patches of thickened, itchy, and irritated skin. It often appears on the legs, although it can also affect the arms, neck, and scalp.

Here are some key features of LSC:

Itchy rash: The primary symptom is an intense itch that can become quite severe. Scratching the affected area may temporarily relieve the itch, but it can also worsen the condition and lead to further inflammation and thickening of the skin.

Thickened skin: The affected skin may become thickened and leathery due to chronic scratching and rubbing. This can give the skin a rough, scaly appearance.

Darker edges: The rash may have darker edges or borders, especially in darker-skinned individuals.

Small spots: Small spots or bumps may appear around the rash. These spots may resemble pimples or small blisters and can sometimes be filled with clear fluid.

Spread from pores: The rash may appear to spread from pores, giving the impression that it is originating from within the skin.

LSC is often caused by repeated scratching or rubbing of the skin. It can be triggered by various factors, including dry skin, eczema, insect bites, allergies, or underlying medical conditions. Emotional stress and anxiety can also contribute to LSC.

If you suspect you have LSC, it's important to consult a dermatologist for proper diagnosis and treatment. The doctor may recommend topical medications, oral medications, lifestyle modifications, or other therapies to manage the condition and relieve symptoms.