Dermatitis is one of the most common skin diseases. There are several types of dermatitis.
Allergic dermatitis, contact dermatitis, atopic dermatitis, nummular dermatitis, sebrrheic dermatitis, etc.
Allergic dermatitis occurs by an allergic reaction to material in contact with the skin. It develops some hours after contact with the problematic material, and settles down after several days if the skin is no longer in contact with that material.
It is a kind of immune reaction that occurs only in people who are hypersensitive to
specific chemicals. Symptoms are skin redness, blistering and itching(usually severe).
Contact dermatitis is a skin inflammation that occurs by a substance that irritates skin. Many chemicals can induce contact dermatitis, including materials found in soaps, household cleaners, metal jewelry, laundry detergents, industrial solvents, cosmetics, perfumes, etc.
Symptom in mild cases is only mild redness of the skin. In more severe cases,
there may occur swelling, blistering or even ulceration.
Atopic dermatitis - If your baby is suffering from atopic dermatitis, please click here.

note :
The information provided is of a general nature and should not be used as a substitute for professional medical advice. To diagnose clearly you should discuss with your family doctor.