What does the diagnosis code 309.9 mean?

The ICD-10 code 309.9 stands for "Atopic dermatitis, unspecified." It is a diagnosis code used to describe a type of chronic inflammatory skin condition that causes itchy, red, and scaly rashes. Atopic dermatitis is commonly known as eczema and is often associated with other allergic conditions such as asthma and hay fever. The unspecified code 309.9 is used when the specific type of atopic dermatitis is not specified or cannot be determined.