What term describes an abnormal inflammatory condition of the skin?

The term that best describes an abnormal inflammatory condition of the skin is dermatitis. Dermatitis refers to a broad category of skin inflammation, characterized by symptoms such as redness, swelling, itching, and possibly blistering or peeling. This condition indicates that the skin is reacting to an irritant or allergen, which could be due to various external factors, such as soaps, lotions, or certain fabrics, or internal factors like stress or allergies.

Chloasma is a term specifically referring to a discoloration of the skin that often occurs during pregnancy, commonly known as the "mask of pregnancy." It does not primarily describe an inflammatory condition.

Cellulitis is a bacterial infection of the skin and underlying tissues that leads to inflammation, but it is not simply classified as a skin inflammatory condition. Instead, it is a serious infection requiring medical attention.

Psoriasis is a chronic autoimmune condition that causes rapid skin cell production, leading to red, scaly patches, which can be considered an inflammatory condition but is specifically categorized as a different type of skin disorder.

Thus, dermatitis is the most appropriate term for a broad abnormal inflammatory condition of the skin, distinguishing it from the more specific or different conditions described by the other terms.