pl. dermatitides pl. dermatitises [dermato- + -itis]
An inflammatory rash marked by itching and redness.
SEE: eczema

Dermatitis has many causes, including contact with skin irritants (such as the oil that causes poison ivy or poison oak); venous stasis, with edema and vesicle formation near the ankles; habitual scratching, as is found in neurodermatitis; dry skin, as in winter itch; and ultraviolet light, as in photosensitivity reactions.

No laboratory testing is usually necessary; diagnosis is made by observation of the skin irritation (usually red, rough plaques) and the location on the body (face, neck and upper trunk).

When a source of dermatitis is identifiable (such as in contact dermatitis due to a detergent or topical cosmetic), the best treatment is to avoid the irritating substance and to cleanse the affected area immediately with mild soap and water. Once skin inflammation becomes established, topical corticosteroid ointments or systemic steroids (during extreme exacerbations), topical immunomodulating agents (in patients over 2), weak tar preparations and ultraviolet B light therapy (to increase the thickness of the stratum corneum), and antihistamines may be used, with antibiotics reserved for secondary infections. Dermatologists may prescribe occlusive dressings intermittently to help clear lichenified skin.

The patient should avoid known skin irritants. Tepid baths, cool compresses, and astringents sometimes help relieve inflammation and itch. Moisturizing creams or lotions following bathing help to retain skin moisture, but perfumed products should be avoided. Drug therapy is administered and evaluated for desired effects and adverse reactions. The patient is taught to apply topical medications and is informed about their most common side effects. Scratching is discouraged and the fingernails kept short to limit excoriation. The patient should be made aware that drowsiness may occur with antihistamine use and that driving or operating mechanical equipment should be avoided until the extent of this effect is known. Health care professionals should be careful not to show any negative feelings when touching lesions during assessment or treatment but should follow standard precautions. Skin changes alter body image, and the patient will need assistance in accepting and coping with what he or she may view as disfigurement. Children and adolescents may require and benefit from counseling to help them deal with the emotional components of their condition.

Descriptive text is not available for this image


actinic dermatitis

Dermatitis that is usually seen on the face or exposed skin surfaces and typically results from exposure and sensitization to ultraviolet rays. Adults over age 50 may be affected.

Descriptive text is not available for this image

SYN: SEE: photosensitivity dermatitis

allergic contact dermatitis

SEE: Contact dermatitis.

atopic dermatitis

Chronic dermatitis of unknown cause found in patients with a history of allergy. The disease usually begins after the first 2 months of life, and those affected may experience exacerbations and remissions throughout childhood and adulthood. In many cases, there is a family history of allergy or atopy. If both parents have atopic dermatitis, the chances are nearly 80% that their children will have it. Atopic dermatitis is typically found in flexural creases of the body, e.g., the antecubital and popliteal fossae. The skin lesions consist of reddened, cracked, and thickened skin that can become exudative and crusty from scratching. Scarring or secondary infection may occur. Most patients have an elevated level of immunoglobulin E in their serum.

Descriptive text is not available for this image


The patient should avoid soaps and ointments. Bathing is kept to a minimum, but bath oils may help to prevent drying of the skin. Clothing should be soft textured and should not contain wool. Fingernails should be kept short to decrease damage from scratching. Antihistamines may help reduce itching at night. Heavy exercise should be avoided because it induces perspiration. A nonlipid softening lotion followed by a corticosteroid in a propylene glycol base may effectively treat acute exacerbations; when large areas of the body are involved, oral steroids may be needed. Because of the adverse effects associated with corticosteroids, topical immunosuppressants such as tacrolimus that decrease T-cell activity have been developed. Antistaphylococcal antibiotics may be needed to control secondary infection, introduced when scratching causes microfissures in the skin.

Descriptive text is not available for this image


berloque dermatitis

berlock dermatitis A type of phytophotodermatitis with postinflammatory hyperpigmentation at the site of application of perfumes or colognes containing oil of bergamot.
SYN: SEE: bergamot phototoxicity.

dermatitis calorica

Dermatitis due to heat, as in sunburn, or cold.

cercarial dermatitis

SEE: Swimmer's itch.

contact dermatitis

Dermatitis due to contact with allergens or an irritating substance. Allergic contact dermatitis is caused by a T-cell-mediated hypersensitivity reaction to natural or synthetic environmental allergens. These combine with skin proteins, altering the normal autoantigens so that new, foreign antigens are created. Nonallergic contact dermatitis, also known as irritative contact dermatitis, is usually caused by exposure to detergent, soap, or other skin irritant.
SYN: SEE: allergic contact dermatitis; SEE: dermatitis venenata (1)

Descriptive text is not available for this image

CONTACT DERMATITIS Allergic reaction to topical anesthetic

Skin changes, which appear 4 to 48 hr after exposure, depending on the degree of sensitivity to the allergen, consist of erythema, local edema, and blisters. The blisters may weep in severe cases. Most patients complain of intense itching. Signs and symptoms of the disease usually last 10 to 14 days. Reexposure to the cause will trigger a relapse.

Tepid baths, cool compresses, topical astringents (such as solutions of aluminum acetate), antihistamines, and corticosteroids all provide some relief.

Descriptive text is not available for this image

CONTACT DERMATITIS Allergic reaction to topical anesthetic

contagious pustular dermatitis

Dermatitis of sheep and goats caused by Parapoxvirus, a genus of poxvirus, and transmitted to humans by direct contact. The lesion on humans is usually solitary and on the hands, arms, or face. This maculopapular area may progress to a pustule up to 3 cm in diameter and may last 3 to 6 weeks.
SYN: SEE: orf

diaper dermatitis

SEE: Diaper rash.

exfoliative dermatitis

Generalized dermatitis involving at least half the body surface area.
When skin involvement is extensive, the patient may become depressed because of the cosmetic changes.

It may be caused by allergic drug reactions (such as vancomycin or penicillins), other allergies, infiltration of the skin by leukemias or lymphomas, atopy, or psoriasis.

Symptoms include extensive skin redness, swelling, itching, thickening, scaling, often with loss of hair follicles, and swelling of lymph nodes.

The disease is diagnosed by physical assessment of the skin and may be confirmed by biopsy if there is any doubt.

When exfoliative dermatitis results from a drug reaction, withholding the offending agent will usually allow the skin to clear within a few weeks. Lymphomatous exfoliative dermatitis is treated with chemotherapy to combat the primary tumor.

Patients with widespread dermatitis often need hospitalization to maintain normal body temperature, normal hydration, adequate wound care, and symptomatic relief.

SYN: SEE: Leiner disease

factitial dermatitis

Deliberately self-inflicted irritation or injury to the skin.

dermatitis herpetiformis

A chronic dermatitis characterized by erythematous, papular, vesicular, bullous, or pustular lesions with a tendency to grouping and with intense itching and burning.

It is associated with allergy to gluten and is often found in patients with celiac disease (gluten-sensitive enteropathy).

The lesions develop suddenly and spread peripherally. The disease is variable and erratic, and an attack may be prolonged for weeks or months. Secondary infection may follow trauma to the inflamed areas.

The disease is diagnosed by physical assessment of the skin and may be confirmed by biopsy if there is any doubt.

Oral dapsone provides substantial relief of symptoms in a few days. Sulfapyridine also may be used.

dermatitis hiemalis

SEE: Winter itch.

incontinence-associated dermatitis

Dermatitis affecting the perineum, upper thighs, or intergluteal folds resulting from chronic exposure to urine or stool.

dermatitis infectiosa eczematoides

Dermatitis during or after a pyogenic disease.

livedo-like dermatitis

SEE: Nicolau syndrome.

meadow dermatitis

A blistering dermatitis that appears on the exposed skin of hikers, florists, gardeners, and those who work outdoors in bright sunlight. It is a phototoxic reaction caused by exposure to light-sensitizing chemicals in some plants (such as parsley, rue, bergamot, or figs).

dermatitis medicamentosa

SEE: Drug rash.

dermatitis multiformis

A form of dermatitis with pustular lesions.

dermatitis papillaris capillitii

Dermatitis on the scalp and neck, composed of papules interspersed with pustules. The rash ultimately produces scarlike elevations resembling keloids.

photoallergic contact dermatitis

SEE: Photoallergy.

photosensitivity dermatitis

SEE: Actinic dermatitis.

poison ivy dermatitis

Dermatitis resulting from irritation or sensitization of the skin by urushiol, the toxic resin of plants of the genus Toxicodendron (Rhus). There is no absolute immunity. Susceptibility varies greatly, even in the same individual.
Those sensitive to poison ivy may also react to contact with other plants, such as the mango rind and cashew oil. These plants contain chemicals that cross-react with the sap present in poison ivy, poison oak, and poison sumac.

Some time elapses between skin contact with the poison and first appearance of symptoms, varying from a few hours to several days, depending on the sensitivity of the patient and the condition of the skin. Moderate itching or a burning sensation is soon followed by small blisters; later manifestations vary. Blisters usually rupture and are followed by oozing of serum and subsequent crusting.

The disease is diagnosed by physical assessment of the skin and may be confirmed by biopsy if there is any doubt.

Some barrier creams have been used to prevent poison ivy dermatitis. They are sprayed on the skin before anticipated contact with the plant.

In mild dermatitis, antihistamines and a lotion to relieve itching are usually sufficient. In severe dermatitis, cool, wet dressings or compresses, potassium permanganate baths, and topical corticosteroids are often effective. In some instances, intramuscular or oral corticosteroid therapy is used. If plant leaves are burned and the smoke inhaled, or if plant leaves are ingested, the patient should be directed to an emergency care center. Demulcents, fluids, morphine, and a high-protein, low-fat diet may be prescribed.

Prevention is important in those with known sensitivity or in those with no previous contact with or reaction to the plant. Instruction of the patient focuses on helping him or her to recognize the plant, to avoid contact with it, and to wear long-sleeved shirts and long pants in wooded areas. If contact occurs, the patient should wash with soap and water immediately to remove the toxic oil. Contaminated clothing and pets also should be promptly and thoroughly washed because contact with such items may cause poison ivy dermatitis in other members of the household.

Descriptive text is not available for this image


primary dermatitis

Dermatitis that is a direct rather than an allergic response.

radiation dermatitis

Dermatitis due to radiation exposure.
SYN: SEE: radioepidermitis; SEE: radioepithelitis; SEE: radiodermatitis

radiation recall dermatitis

SEE: Radiation recall.

rhus dermatitis

Contact dermatitis caused by the toxic resin in poison ivy or oak.
SEE: poison ivy dermatitis; SEE: Toxicodendron

schistosome dermatitis

SEE: Swimmer's itch.

dermatitis seborrheica

An acute or subacute dermatitis of unknown cause, beginning on the scalp and/or face and in skin folds (any area where sebaceous glands are active) and characterized by rounded, irregular, or circinate lesions covered with yellow or brown-gray greasy scales.
SYN: SEE: pityriasis capitis; SEE: seborrhea corporis; SEE: seborrhea sicca

The scalp may be dry with abundant grayish branny scales or oozing and crusted (eczema capitis). The rash may spread to the forehead and postauricular regions. The forehead shows scaly and infiltrated lesions with dark red bases and localized loss of hair. The eyebrows and eyelashes may have dry, dirty white scales. Inflamed skin and scales may be present on the nasolabial folds or the vermilion border of the lips. On the sternal region, the lesions are greasy to the touch. Eruptions may also appear in interscapular, axillary, and genitocrural regions. Cold winter weather may worsen the condition.

The disease is diagnosed by physical assessment of the skin and may be confirmed by biopsy if there is any doubt.

When the condition is limited to the scalp, frequent shampooing and use of mild keratolytic agents are indicated. Shampoos containing selenium are helpful. Generalized seborrheic dermatitis requires scrupulous skin hygiene, frequent washing and shampooing with selenium sulfide suspension to remove scales, keeping the skin as dry as possible, and using dusting powders. Fluorinated corticosteroids may be applied topically to hairless areas, and systemic cortisone preparations may be required. The differential diagnosis includes psoriasis, which should be ruled out; neurologic conditions should be recognized as possible predisposing factors.

The health care provider explains to the patient that the condition has remissions and exacerbations and that hormone imbalances, nutritional status, infection, and emotional stress influence its course. The patient is taught to apply prescribed corticosteroids to the body and face. Fluorinated corticosteroids should be used with caution near the eyelids, on the face, and in the groin. To avoid developing a secondary Candida yeast infection in body creases or folds, the patient is advised to cleanse these areas carefully, to dry gently but thoroughly, and to ensure that the skin is well aerated. He or she is taught to treat seborrheic scalp conditions (dandruff) with proper and frequent shampooing, alternating two or three different types of shampoo to prevent the development of resistance to a particular product. External irritants and excessive heat and perspiration should be avoided. Rubbing and scratching the skin are discouraged because they prolong exacerbations and increase the risk for secondary infection and excoriation, esp. since scaly, pruritic lesions present in skin areas with high bacteria counts. Oral antibiotics (such as tetracycline) may be prescribed (as for acne vulgaris) in low doses over a prolonged period to reduce bacterial colonization. The patient is advised to take tetracycline at least 1 hr before or 2 hr after meals, since the drug is poorly absorbed with food. The patient also is taught about the adverse effects of the drug (photosensitivity, birth defects, nausea, vomiting, and candidal vaginitis) and their management. Adherence to the treatment regimen is necessary to achieve optimal results. Psychological support or counseling is provided as necessary to deal with related body image concerns.

stasis dermatitis

Dermatitis of the legs with edema, pigmentation, and sometimes chronic inflammation. It is usually due to impaired return of blood from the legs. Compression stockings help the rash to resolve gradually.

Descriptive text is not available for this image

Descriptive text is not available for this image


dermatitis venenata

SEE: 1. Contact dermatitis.
2. Any inflammation caused by local action of various animal, vegetable, or mineral substances contacting the surface of the skin.

dermatitis verrucosa

A chronic fungal infection of the skin characterized by the formation of wartlike nodules. These may enlarge and form papillomatous structures that sometimes ulcerate.

This condition may be caused by any of several fungi, including Hormodendrum pedrosoi or Phialophora verrucosa.