As one of the most exposed areas of the body, the arms are a frequent site of skin rashes. Infections, allergic skin reactions and contact with environmental irritants commonly cause skin rashes on one or both arms. Although most rashes do not pose a serious health threat, infectious skin rashes often require treatment to prevent potentially serious complications.
Allergic Contact Dermatitis
Eczema describes a group of skin conditions characterized by itchy, red skin patches. Allergic contact dermatitis is a common form of eczema in which direct physical contact with an allergy-stimulating substance provokes a local skin reaction. Nickel found in costume jewelry commonly triggers allergic dermatitis, according to the patient information website EczemaNet. Nickel-containing bracelets commonly cause a red, itchy rash on the lower forearm and wrist.
Poison ivy, sumac and oak are commonly encountered triggers of allergic contact dermatitis. The plants produce the oil urushiol. Initial exposure to urushiol typically does not cause a skin reaction. Subsequent exposure, however, often provokes an allergic skin reaction that develops within 12 to 72 hours. The American Academy of Dermatology says that approximately 85 percent of people have an allergic reaction to urushiol. The reaction typically causes skin redness, itching and swelling followed by the development of blisters in the areas of urushiol contact. The arms and hands are common sites of inadvertent contact with poison ivy, sumac and oak.
Atopic Dermatitis
Atopic dermatitis is another variant of eczema that often involves the skin of the arms. Most people develop atopic dermatitis in the first few years of life. The head and face are most commonly involved in infants and young children. When the condition persists into later childhood and young adulthood, the elbows and knees are more commonly affected, according to the American Academy of Dermatology. Involved skin areas appear red and dry; scaling and skin thickening may develop in chronically involved areas. Persistent itching is a hallmark characteristic of atopic dermatitis.
Cellulitis
Cellulitis is a spreading bacterial infection of the deep layers of the skin. The skin is composed of three layers--the epidermis, dermis and subcutaneous tissue. Cellulitis involves infection of the dermis and subcutaneous skin layers. The infection most commonly arises from a small break in the skin that furnishes a route of entry for the infecting bacteria. Minor cuts, scratches, insect bites or superficial skin infections can lead to the development of cellulitis. Although cellulitis most commonly develops in the legs, the arms are also frequent sites of infection.
Cellulitis appears as an area of red, warm, swollen skin. The area of redness expands as the infection spreads. Fever commonly accompanies the development of cellulitis, according to the patient information website InteliHealth. Early diagnosis and antibiotic treatment help prevent the possible spread of the infection to the bloodstream.
References
- EczemaNet: Contact Dermatitis
- American Academy of Dermatology: Poison Ivy, Oak and Sumac
- American Academy of Dermatology: Eczema/Atopic Dermatitis
- InteliHealth: Cellulitis
- "Principles and Practice of Infectious Diseases, Sixth Edition"; Gerald L. Mandell, M.D., et al., Editors; 2004
