Excerpt from Dermatitis, Exfoliative

Synonyms, Key Words, and Related Terms: erythroderma, epidermis, epithelial layer, epithelial cells, scaling eruption

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Background: Exfoliative dermatitis, or erythroderma, is an erythematous, scaly dermatitis involving most, if not all, of the skin. This generalized scaling eruption of the skin is drug induced, idiopathic, or secondary to underlying cutaneous or systemic disease.

Appreciation for this condition requires an understanding of the skin's normal epithelial layer. Normal epidermis has a continual turnover of epithelial cells. Cell division occurs near the basal layer. As cells move toward the periphery, they become well keratinized. This process requires approximately 10-12 days. Cells subsequently remain in the stratum corneum for another 12-14 days prior to being sloughed off.

In exfoliative dermatitis, the mitotic rate in the basal layer increases and overall transit time decreases; therefore, more cells are lost from the surface. The mechanism responsible for this is not known, although an immunologic basis has been suggested.

Pathophysiology: Exfoliative dermatitis may occur in response to drug therapy, systemic disease, or an idiopathic entity. As many as 40% of cases involve preexisting cutaneous disease. Approximately 10% of cases are the result of drug reactions. As many as 40% are caused by underlying systemic disease. The remaining cases are idiopathic.

Histopathologic patterns observed for drug-induced and idiopathic causes of exfoliative dermatitis are nonspecific. Biopsy findings in individuals with preexisting cutaneous or systemic disease during an exfoliative stage may reveal, inconsistently, the underlying skin lesion or pathology. Through multiple-biopsy histologic analysis, the diagnosis may be confirmed in as many as 45% of patients.

Frequency:

In the US: An estimated 1% of hospitalizations are for skin disease.

Internationally: The ratio of hospitalized patients experiencing adverse drug reactions is 3 in 1000. According to 1 large Finnish study, approximately 1% of these instances involve exfoliative dermatitis.

Mortality/Morbidity: Mortality approaches 30%. In a report of 108 patients with exfoliative dermatitis who were autopsied, 87 died from the underlying disease. No cause other than exfoliation was found for the remaining 17 patients.

Race: Exfoliative dermatitis occurs in all races. In the young black male population, recent research suggests exfoliative dermatitis may be a marker for HIV infection.

Sex: The male-to-female ratio is 2:1.

Age: Individuals older than 40 years are affected most frequently.