L98: Other disorders of skin and subcutaneous tissue, not elsewhere classified

L98.3: Eosinophilic cellulitis [Wells]

The exact cause of a rash like this is unknown.

Initially, the skin is often itchy and burning. The skin turns red at the places affected, and it can swell up. Blisters or scales may also form in the places affected. You may also be very tired and have joint pain.