Dermatitis

(Eczema)

Superficial inflammation of the skin.

Causes of dermatitis include exposure to irritants or, much less commonly, to allergens (delayed hypersensitivity); genetic factors; and idiopathic factors.

Symptoms, Signs, and Diagnosis

Dermatitis occurs when pruritus, erythema, and edema progress to vesiculation, oozing, crusting, and scaling. Repeated rubbing or scratching may cause the skin to thicken or to develop prominent markings (lichenification). Pruritus is often accompanied by excoriation; papules and lichenified areas may be present. Frequently, the skin is dry with fine scaling.

Diagnosis is generally made clinically. If an allergen is suspected because of recurrent or unresponsive disease, patch testing can be helpful.

Treatment

Patients should avoid any practice or product that might irritate the skin, such as excessive use of soaps and detergents. Clothing made of nonirritating fabrics, such as cotton, is preferred. An emollient can be helpful if used liberally, especially after bathing. A medium-potency corticosteroid ointment may be applied to affected areas 3 times daily to help relieve pruritus and control inflammation. If the skin remains dry, an emollient can be applied between applications of the corticosteroid ointment. Once symptoms are alleviated, the corticosteroid ointment can be used less often or even discontinued, but emollient use should continue.

An antihistamine may reduce pruritus and help the patient sleep. However, in the elderly, antihistamines must be used cautiously because they are strongly anticholinergic; they rarely produce a benefit that justifies the risk.

Phototherapy with ultraviolet B (UVB) or photochemotherapy with psoralens plus ultraviolet A (PUVA) is sometimes effective; however, these therapies are often inconvenient for the patient because supervised treatments at the phototherapy facility are required 2 or 3 times a week for several weeks. Therefore, they are usually considered only after all other treatment options have been tried.

Seborrheic Dermatitis

A chronic disorder characterized by a scaly, erythematous eruption affecting mainly the face, scalp, and presternal area.

Although seborrheic dermatitis of the scalp (dandruff) is common in all age groups after puberty, involvement of the face and chest is rare before middle age and is most common in the elderly, particularly those with compromised skin care.

Despite its name, seborrheic dermatitis appears to have nothing to do with sebum. A hypersensitivity response to the usually nonpathogenic yeast Pityrosporum ovale may play a key role in pathogenesis.

The eyebrows, eyelids (causing seborrheic blepharitis and conjunctivitis), nasolabial folds, and postauricular and beard areas are most commonly affected, but the central chest and interscapular areas can also be affected.

Seborrheic dermatitis of the scalp can be treated with various shampoos containing sulfur, zinc pyrithione, salicylic acid, sulfur, tar, ketoconazole, or a combination of these. If shampooing is inconvenient or physically impossible, the patient can use topical 1% hydrocortisone lotion, especially in severe cases.

Seborrheic dermatitis of the face and trunk can be treated with hydrocortisone 1% cream. Preparations containing ketoconazole, sulfacetamide, sulfur, or salicylic acid are also helpful.

Seborrheic blepharitis can be treated with hydrocortisone 1% cream (ophthalmic formulation). If associated conjunctivitis requires intraocular administration of a corticosteroid ointment or suspension, an ophthalmologist may need to monitor intraocular pressure. Warm compresses and gentle cleaning with diluted baby shampoo on a cotton-tipped swab to lid margins facilitates the removal of crust and scales.

Lichen Simplex Chronicus

(Neurodermatitis)

A localized pruritic thickening of the skin resulting from repeated scratching.

Lichen simplex chronicus is common in the elderly. It occurs in patients with pruritus at sites that are readily accessible for scratching, eg, the lateral aspect of the ankle, dorsum of the foot, shin, back of the neck, forearm, and elbows.

Lesions are dry, scaling, well-circumscribed, hyperpigmented, lichenified plaques (thickened skin with accentuated markings) of oval, irregular, or angular shape.

A high-potency topical corticosteroid is often used to control symptoms. A corticosteroid-impregnated tape (eg, with flurandrenolide) can help deliver the medication and provide a mechanical barrier to help break the itch-scratch cycle. When symptoms lessen, the corticosteroid potency can be reduced. Intralesional corticosteroids, such as triamcinolone 5 mg/mL (2 to 5 mg total dose per lesion), are often helpful for more troublesome lesions. Tar-containing preparations may also relieve symptoms.

More extensive lesions at some sites, such as the forearms and legs, can be covered for a week at a time with an Unna's boot (a firm paste bandage). This treatment helps break the itch-scratch cycle and often alleviates symptoms within 1 week.

Phototherapy may be tried when other treatments have failed.

Stasis Dermatitis

(Gravitational Eczema; Varicose Eczema)

Inflammation associated with venous hypertension in the lower legs.

The pathogenesis is unknown. Stasis dermatitis may be exacerbated by edema, contact dermatitis due to use of topical medications, and scratching. Continued venous hypertension, even in the absence of stasis dermatitis, is a risk factor for venous ulceration.

Affected skin in the lower legs is eczematous and usually is edematous, with hemosiderin pigmentation and dilatation of superficial venules around the ankles.

The affected limb must be elevated at least to heart level to facilitate venous return. Compression can be continuous or intermittent and should be increased over days to weeks to 30 to 40 mm Hg of pressure with use of surgical tube stockings and elastic bandages. Compression therapy may need to be continued even if the condition appears to have improved. However, aggressive compression may lead to ischemia in patients with arterial insufficiency, particularly diabetics. Thus, if arterial insufficiency is likely, ankle-brachial indexes and other vascular studies should be performed before initiating compression therapy.

A low- to mid-potency topical corticosteroid (eg, hydrocortisone 1% ointment or triamcinolone 0.1% ointment) may help relieve pruritus, scaling, and inflammation. Any possible contact allergen (eg, bacitracin, neomycin, fragrance) should be avoided.