Contact Dermatitis - Brief Introduction

Definition: Contact dermatitis can be defined as a red, itchy rash caused by any substance that comes in contact with the skin.

It could be caused by an allergy, or because the protective layer of the skin gets damaged.

There are two main types of contact dermatitis

1. Irritant contact dermatitis: common nonallergic reaction due to weak acids or alkalis (e.g. detergents). Often seen on the hands. Erythema is typical, crusting and vesicles are rare

2.Allergic contact dermatitis: type IV hypersensitivity reaction. Uncommon often seen on the head following hair dyes. Presents as an acute weeping eczema which predominately affects the margins of the hairline rather than the hairy scalp itself. Topical treatment with a potent steroid is indicated.

Clinical Signs And Symptoms: 

• Only the superficial regions of the skin are affected in contact dermatitis. Inflammation of the affected tissue is present in the epidermis (the outermost layer of skin) and the outer dermis (the layer beneath the epidermis)
• Contact dermatitis results in large, burning, and itchy rashes. These can take anywhere from several days to weeks to heal. This differentiates it from contact urticaria (hives), in which a rash appears within minutes of exposure and then fades away within minutes to hours. Even after days, contact dermatitis fades only if the skin no longer comes in contact with the allergen or irritant.
• Red rash or bumps
• Itching, which may be severe
• Dry, cracked, scaly skin, if your condition is chronic
• Blisters, draining fluid and crusting, if your reaction is severe.

Diagnosis:  To diagnose a case of contact dermatitis the genera; physician may need to  refer the patient to an allergy specialist or dermatologist to pinpoint the cause of contact dermatitis. The specialist can perform allergy testing (called a ‘patch test’), which involves exposing a small patch of the skin to an allergen. If the skin reacts, the allergy specialist can determine the likely cause of the contact dermatitis

Management:

1. If the substance that caused the rash is identified completely avoid it later and never touch it.

2. Wash the skin with mild soap and cool water right away, if possible. This helps get rid of all or most of the problem substance. and could help cut back on symptoms.

3. Applying prescription steroid creams can help if initial home remedies fail.

4. In severe cases, the doctor may prescribe oral corticosteroids to reduce inflammation, antihistamines to relieve itching or antibiotics to fight a bacterial infection.