Chapter 131: Contact Dermatitis

Patient Story

An 11-year-old girl presents with a rash on her abdomen for the past month (Figure 131-1).

She denies other skin problems but her mother states that she had atopic dermatitis as a baby. The clinician readily identifies the problem as a nickel allergy to the nickel found in her belt buckle and jeans. He prescribes avoidance of nickel contact to the skin and prescribes 0.1 percent triamcinolone ointment to be applied twice daily until the contact dermatitis resolves. He describes various methods to cover medal snaps intense including sewing and fabric or painting clear nail polish over the metal. Neither method works 100 percent but it is hard to find jeans without metal snaps. The patient responded rapidly to treatment.^1,2

Introduction

Contact dermatitis (CD) is a common inflammatory skin condition characterized by erythematous and pruritic skin lesions resulting from the contact of skin with a foreign substance. Irritant contact dermatitis (ICD) is caused by the non–immune-modulated irritation of the skin by a substance, resulting in a skin changes. Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity reaction in which a foreign substance comes into contact with the skin, and upon reexposure, skin changes occur.³

Epidemiology

• Some of the most common types of CD are secondary to exposures to poison ivy, nickel, and fragrances.⁴

• Patch testing data indicate that the five most prevalent contact allergens out of more than 3700 known contact allergens are nickel (14.3% of patients tested), fragrance mix (14%), neomycin (11.6%), balsam of Peru (10.4%), and thimerosal (10.4%).⁵

• Occupational skin diseases (chiefly CD) rank second only to traumatic injuries as the most common type of occupational disease. Chemical irritants such as solvents and cutting fluids account for most ICD cases. Sixty percent were ACD and 32 percent were ICD. Hands were primarily affected in 64 percent of ACD and 80 percent of ICD⁴ (Figure 131-2).

Etiology and Pathophysiology

• CD is a common inflammatory skin condition characterized by erythematous and pruritic skin lesions resulting from the contact of skin with a foreign substance.

• ICD is caused by the non–immune-modulated irritation of the skin by a substance, resulting in a skin ...