Dermatitis is INFLAMMATION, redness (erythema), and itching of the SKIN. Dermatitis has many causes and manifests in numerous and varied presentations, some of which may reflect conditions such as viral INFECTION, AUTOIMMUNE DISORDERS, and certain kinds of CANCER. Dermatitis may be acute (come on suddenly) or chronic (persist or recur over an extended period of time).
A chronic condition also called eczema, atopic dermatitis typically first appears in infancy or early childhood and often persists, in periods of exacerbation and REMISSION, throughout life. Symptoms include areas of red, cracked, weepy (oozing) sorelike eruptions that eventually crust, scale, and thicken. Itching is intense. The most frequent areas of involvement are the surfaces on the inner (antecubital) surface of the elbows and the back (popliteal) surface of the knees, though atopic dermatitis can affect any part of the body. Atopic dermatitis seems to have a hereditary component, as it runs in families, and is more common in people who have hypersensitivity conditions such as ALLERGIC RHINITIS.
People who have, or who have ever had, atopic dermatitis should not receive vaccination against SMALLPOX that uses the vaccinia virus (the vaccine administered by health-care providers in the United States). This vaccine can cause a particularly serious eruption of atopic dermatitis.
Treatments for atopic dermatitis outbreaks include topical skin lubricants, such as ointments and lotions that help the skin retain moisture, and topical CORTICOSTEROID MEDICATIONS. The dermatologist may prescribe a course of oral corticosteroid medication (such as prednisone) for severe or resistant symptoms. Oral ANTIHISTAMINE MEDICATIONS may help control itching. Scratching excoriates the lesions, setting the stage for bacterial infection, which then requires ANTIBIOTIC MEDICATIONS.
Atopic dermatitis outbreaks vary in severity and length. Atopic dermatitis abates in some children as they reach ADOLESCENCE or early adulthood, though dermatologists believe the condition goes into an extended state of remission rather than disappears. In some adults, the only indications that atopic dermatitis persists are fissures and cracks in the skin on the palms of the hands and the soles of the feet, which may appear to be exceedingly dry skin rather than dermatitis. Coating the palms and soles with petroleum jelly at bedtime, protecting the coating with mittens and socks, often helps heal the fissures. About 10 percent of the American population has atopic dermatitis.
Numerous environmental substances, from plant resins (poison ivy) to metals (nickel, stainless steel) to bath soaps and laundry detergents, can irritate and inflame the skin. Contact dermatitis may represent an allergic response in which the IMMUNE SYSTEM, particularly the Langerhans cells located in the dermis, overreacts to a substance. Allergic contact dermatitis generally appears within 24 hours of contact, while weeks or even months of exposure to irritants may take place before causing contact dermatitis. The location of the first point of outbreak often helps narrow the field for identifying the cause.
Treatment is twofold: removing the offending irritant or ALLERGEN, and treating the symptoms. Oral antihistamine medications and topical corticosteroids typically reduce itching and inflammation. It may take up to three months for all symptoms of contact dermatitis to resolve. Contact dermatitis can be a matter of OCCUPATIONAL HEALTH AND SAFETY when the offending substance is necessary in the workplace. People who work with glues, paints, metals, plastics, latex rubber, and numerous industrial chemicals commonly develop contact dermatitis.
An uncommon but serious form of dermatitis in which the epidermis (outer layer of the skin) becomes inflamed and forms scales that peel away, exfoliative dermatitis nearly always indicates systemic disease, frequently a cancer such as LEUKEMIA, cutaneous T-cell lymphoma (CTCC), or LYMPHOMA. Exfoliative dermatitis may be the earliest sign of PROSTATE CANCER, THYROID CANCER, and COLORECTAL CANCER. It also develops in people who have AIDS, and may occur as an ADVERSE REACTION to numerous medications.
Exfoliative dermatitis begins with patches of skin (lesions) that turn red and itch. Within two weeks the lesions spread to cover nearly the entire surface of the skin except the soles of the feet, palms of the hands, and face (though usually spare the mucous membranes). The scaling and dilation of blood vessels that follow significantly impairs all dermal functions from IMMUNE RESPONSE to thermal regulation (heat loss). Fluid oozes continually from the exposed dermis and the BLOOD vessels are dilated, causing excessive cooling that easily becomes HYPOTHERMIA. Damage to the protective epidermis exposes the inner layers of skin and tissues to infection.
Treatment aims to restore skin integrity and function as well as to remedy any underlying disorder. Symptomatic treatment typically includes oral antihistamines to control itching, topical corticosteroids to reduce inflammation, and warm baths. Prolonged or chronic exfoliative dermatitis may require IMMUNOSUPPRESSIVE THERAPY such as psoralen plus ultraviolet-A (PUVA) therapy or methotrexate. The success of treatment depends on identifying and treating the underlying cause. Idiopathic exfoliative dermatitis tends to recur, with periods of exacerbation alternating with periods of remission.
Circular lesions about the size of coins that crust and weep are the distinctive hallmark of nummular dermatitis. Researchers do not know what causes the lesions to take such a precise form. Sometimes mistaken for tinea corporis (ringworm) at the onset of an outbreak, the lesions begin as red, raised circles that quickly progress. Usually the lesions remain confined to small areas, and typically recur in the same locations. Outbreaks can cause significant itching. As with other forms of dermatitis, antihistamines and topical corticosteroids help control symptoms. Severe or persistent symptoms may require a course of oral or intramuscular corticosteroids.
A common cause of DANDRUFF, seborrheic dermatitis affects the sebaceous structures primarily of the head and face, notably on the scalp, behind the ears, around the eyebrows, and in the beard area on men’s faces. Seborrheic dermatitis may also develop on other parts of the body that have numerous sebaceous structures, such as the chest and axilla (underarms), and typically occurs in a symmetrical pattern. Inflammation stimulates the sebaceous glands to increase sebum production, which in turn accelerates the turnover rate of dermal and epidermal cells that plug the sebaceous ducts and HAIR follicles. Key symptoms of seborrheic dermatitis include oily patches of skin that crust, scale, and flake.
Most seborrheic dermatitis is idiopathic (occurs without identifiable cause) and is more common in people between the ages of 20 and 40. Seborrheic dermatitis that occurs later in life may be a sign of PARKINSON’S DISEASE, though researchers do not fully understand this correlation. Treatments for dandruff are often effective for seborrheic dermatitis, and emphasize reducing sebum production and accumulation.
Restricted or damaged peripheral blood circulation allows fluid to collect between the layers of the skin, causing inflammation and itching characteristic of dermatitis. The skin typically becomes discolored, turning reddish brown, and scaly as the condition persists. People who have DIABETES, VARICOSE VEINS, PERIPHERAL VASCULAR DISEASE (PVD), or INTERMITTENT CLAUDICATION have increased risk for stasis dermatitis, as do people who have restricted mobility or are bedridden. The impaired circulation limits the skin’s ability to resist or fight infection, and can allow the skin to break down into ulcerations that require aggressive medical intervention. Wearing support hose, elevating the legs when sitting or lying down, and walking are measures that help reduce fluid accumulations (edema).
Though each type of dermatitis has unique symptoms, all types share certain symptoms in common. These include lesions that:
The dermatologist often can make the diagnosis based on the appearance, characteristics, and location of the lesions as well as the individual’s age and family health history. When the diagnosis is questionable, the dermatologist may biopsy several lesions for further examination under the microscope. Tests for immune response also may be helpful for confirming a diagnosis.
Antihistamine and corticosteroid medications are the mainstay of pharmacological therapy for nearly all forms of dermatitis. Secondary bacterial infections require treatment with antibiotic medications. Most dermatitis is, or becomes, chronic. Treatment approaches strive to minimize the frequency and severity of outbreaks. Though dermatitis is seldom life-threatening, it can significantly interfere with QUALITY OF LIFE. Researchers continue to explore the causes of dermatitis, looking for ways to suppress symptoms.
The key risk factors for dermatitis are family history and existing allergies. Preventive measures focus on minimizing outbreaks and symptoms. Self-care approaches include
See also ICHTHYOSIS; IMPETIGO; KERATOSIS PILARIS; LESION; LICHEN PLANUS; LICHEN SIMPLEX CHRONICUS; PSORIASIS; RASH; STAPHYLOCOCCAL SCALDED SKIN SYNDROME; TINEA INFECTIONS; TOXIC EPIDERMAL NECROLYSIS; URTICARIA.
Resource: Facts On File Encyclopedia Of Health And Medicine
Xanthoma is a fatty deposit that forms a benign (noncancerous) LESION beneath the SKIN, though also may occur in other tissues. Xanthomas develop in people who have chronic, untreated HYPERLIPIDEMIA (elevated BLOOD cholesterol and triglycerides levels). In their most common form, xanthomas appear as yellowish blebs beneath the skin, typically rounded or
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Toxic Epidermal Necrolysis is a life-threatening inflammatory condition affecting the SKIN and underlying connective tissues, also called Stevens-Johnson syndrome. Toxic epidermal necrolysis usually results as an adverse DRUG reaction though may occur as a complication of INFECTION or CANCER. Doctors believe toxic epidermal necrolysis develops when an
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