American Medical Association Family Medical Guide - American Medical Association [95]
Poison ivy
Touching plants such as poison ivy, poison oak, and poison sumac (see page 169) can cause a severe case of al lergic contact dermatitis in most people, although sensitivity declines with age. Symptoms develop within 24 to 48 hours of exposure and include patches of red bumpy skin or blisters that itch intensely and eventually break open and release a watery discharge. The oil from the plant that causes the initial rash can spread from the area of contact to other parts of the body.
Infantile eczema
Infantile eczema (see page 1062) is a form of atopic dermatitis that causes skin inflammation in infants and small children. It produces an itchy rash or small red pimples, and can be accompanied by oozing blisters that crust over. Infantile eczema can occur anywhere on the body but usually develops on the cheeks or chin, behind the knees, or on the insides of the elbows.
Diaper rash
Diaper rash (see page 386) is slight redness to severe inflammation of the skin around the thighs, genitals, and buttocks in babies (left). It can sometimes be accompanied by a yeast infection that causes tender sores and oozing pimples (right). Skin contact with urine and stool, along with moisture and chafing from the diaper itself, can cause diaper rash.
Eczema
Eczema (see page 1062) appears as red, itchy lumps or blisters on the skin that sometimes join to form patches. When eczema is persistent, the skin in the affected area may become dry and lighter or darker than the surrounding skin, and may look like leather. In nummular eczema, the patches of skin are round, raised, and flaky. The legs (left) and hands (right) are commonly affected sites.
Seborrheic dermatitis Seborrheic dermatitis (see page 1063) is chronic skin inflammation that makes the skin red, flaky, and itchy. In adults, it usually affects the scalp, face, and neck, but it can occur anywhere on the body. Dandruff is a form of seborrheic dermatitis.
Allergic contact dermatitis
Allergic contact dermatitis (see page 1062) is an allergic reaction to a substance such as hair dye, metal, or wool (as on neck in the image at far left). The itchy, flaky skin of allergic contact dermatitis is limited to the area of contact. A metal button made of nickel caused the rash in the illustration at right.
Lumps and Bumps on or Under the Skin
Acne
Acne (see page 1065) is a chronic skin condition in which various types of blemishes recur persistently on the upper part of the body, mostly on the face. Acne blemishes include small dark plugs imbedded in the skin (blackheads), small red lumps, tiny raised white spots (whiteheads), and small to large firm swellings (nodules and cysts). Acne is common in adolescents but can occur at any age.
Shaving bumps
Shaving bumps (known medically as pseudo-folliculitis) are ingrown hairs (see page 1075) that can develop when the sharp ends of shaved hair grow back into the skin and become trapped under the skin. The small, hard bumps that appear around hair follicles cause slight inflammation and are common in men with curly hair. If the hair follicles become infected, the condition is called folliculitis (see page 1076).
Warts
Warts (see page 1060) are small areas of persistent viral infection in the upper layer of skin. The typical common wart is a hard lump with a rough, cauliflowerlike surface (top left). Warts on the bottom of the feet are called plantar warts (top right). Tiny black flecks may be visible in the body of the wart. Flat-topped, flesh-colored warts occur mainly on the wrists, the backs of the hands, and the face (left). Flat warts can itch.
Seborrheic keratoses Seborrheic keratoses (see page 1063) are dark, sometimes rough-surfaced lumps that often appear on the skin in large numbers later in life. They are harmless but can resemble malignant melanoma (see page 1069), a life-threatening form of skin