SLIDESHOW – The many faces of eczema in hands!
June 9, 2010
Dyshidrotic eczema is a chronic relapsing form of vesicular palmoplantar dermatitis of unknown etiology. Although the etiology is unclear, there is a strong association with atopy. Fifty percent of patients with dyshidrotic eczema will also have atopic dermatitis. Exogenous factors, especially metals (such as nickel), may trigger episodes.
Patients typically report pruritus of the hands and feet with a sudden onset of vesicles. On examination, patients will have symmetric crops of clear vesicles and/or bullae on the palms as well as lateral aspects of the fingers and toes, feet, and soles (shown). The distribution of lesions is 80% hands only, 10% feet only, and 10% feet and hands.
Lichen simplex chronicus is a thickening of the skin with variable scaling that arises secondary to repetitive scratching or rubbing. It is not a primary process, but develops when patients sense pruritus, repetitively excoriate the area, and develop lichenification.
The etiology of the pruritus may be due to any underlying pathology, or none at all. Patients typically report stable pruritic plaques, most commonly on the scalp, nape of the neck, extensor forearms, elbows, vulva, scrotum, upper medial thighs, knees, lower legs, and ankles. Erythema is found in early lesions. The plaques are typically well demarcated, lichenified, firm, and rough with exaggerated skin lines. Hyperpigmentation may be present. Treatment is aimed at reducing pruritus with topical corticosteroids or oral antihistamines. In some patients, antianxiety medications are require.
Irritant contact dermatitis is a nonspecific response of the skin to direct chemical damage. It is the clinical result of inflammation arising from the release of proinflammatory cytokines from skin cells, principally keratinocytes.
The major pathophysiologic changes are skin-barrier disruption, epidermal cellular changes, and cytokine release. Although a wide range of chemicals may be responsible, the most common causes are repeated exposure to low-grade irritants, such as soaps and detergents. Acute irritant contact dermatitis may develop within minutes to hours of exposure, whereas the cumulative form may be delayed by weeks. On examination, patients may exhibit macular erythema, hyperkeratosis, or fissuring over vesiculation with a scalded appearance of the epidermis (shown). Healing typically beings promptly after removal of the offending agent, although creams containing ceramides or dimethicone may be useful to help restore the epidermal barrier.
SUGGESTIONS FOR FURTHER READING: