Dermatitis is inflammation of the skin. It is caused by itching, contact with harsh chemicals, or other irritating substances. Symptoms may appear suddenly or gradually, including redness, swelling, rash-like lesions called nodules, oozing, or bleeding. Causes can vary widely and include allergic conditions, autoimmune disorders, bacterial infections, fungal infections, and contact dermatitis, which is when you touch something that you're allergic to. Dermatitis often leads to fever and various forms of physical discomfort. It can also lead to psychological distress if not properly treated promptly. Treatment is usually done either through topical ointments or oral drugs.

The most common form of dermatitis is contact dermatitis which comes from contact with an allergen and irritant. This form of dermatitis can persist for a few days to several months. It often occurs in areas of the body exposed to irritants such as water, detergents, and chemicals. Other substances can also trigger symptoms, including nickel, wool, latex, certain fabrics, and certain foods. Contact with these substances produces redness and itching initially, but a rash may develop if exposure continues.

Parasitic dermatitis is caused by a parasite that enters the body through open wounds or contact with infected blood. This type of dermatitis is a unique medical condition. Usually, it appears as small red spots arranged like stars or smaller lesions on the palms, soles, and legs. The skin may be warm to the touch and may itch. Parasitic dermatitis can be treated with anti-parasitic drugs that are prescribed by a licensed medical professional.

The most common bacterial infection of the skin, cellulitis is caused by staphylococcus aureus or streptococcus pyogenes. It commonly occurs in children or the elderly but can occur throughout life. It is a superficial infection that becomes itchy and inflamed. Staphylococcal dermatitis, also known as impetigo, is limited to the epidermis and may be associated with pre-existing skin conditions such as eczema or atopic dermatitis. This form of skin infection spreads easily from person to person through direct contact.

Infestation with various fungi can cause dermatitis, such as ringworm, athlete's foot, jock itch, and diaper rash. These fungi are everywhere and can live on virtually any surface. The infection spreads from person to person through contact with another infected individual. Fungal dermatitis generally affects only body parts but not the palms or soles.

Dermatitis often has a psychological component that exacerbates the symptoms and may even be a triggering factor for psychiatric illnesses such as depression. Children must be recognized as having a skin disorder, as this emotional disturbance may lead to changes in behavior and academic achievement.