AGE OF ONSET Middle-aged adults.

SEX Males > females.

Etiology

Some 50% of patients have a history of preexisting dermatosis. Most frequent are psoriasis, atopic dermatitis, adverse cutaneous drug reactions, cutaneous T-cell lymphoma (CTCL), allergic contact dermatitis, seborrheic dermatitis, and pityriasis rubra pilaris. Drugs most commonly implicated are shown in Table 8-1. In ⋃30% of patients, it is not possible to identify the cause.

Pathogenesis

The metabolic response to exfoliative erythroderma may be profound. Large amounts of warm blood are present in the skin caused by dilatation of the capillaries, resulting in considerable heat dissipation. Also, there may be high-output cardiac failure; the loss of scales (and thus proteins) through exfoliation can be considerable, up to 9 g/m² of body surface per day.

Depending on the etiology, the acute phase may develop rapidly, usually in a drug reaction, or psoriasis. At this early acute stage, it is still possible to identify the preexisting dermatosis. There is fever, pruritus, fatigue, weakness, anorexia, weight loss, malaise, feeling cold, and shivers.

APPEARANCE OF PATIENT Frightened, red, "toxic," may be malodorous.

SKIN LESIONS Skin is red, thickened, and scaly. Dermatitis is uniform involving the entire body surface (Figs. 8-1, 8-2, 8-3), except for pityriasis rubra pilaris, which has sharply defined areas of normal skin (Fig. 3-16). Thickening leads to exaggerated skin folds (Figs. 8-2 and 8-3); scaling may be fine and branny, and may be barely perceptible (Fig. 8-2) or large, up to 0.5 cm, and lamellar (Fig. 8-1).

Palms and Soles Usually involved, with massive hyperkeratosis and deep fissures in pityriasis rubra pilaris, Sézary syndrome (CTCL), and psoriasis.

HAIR Telogen effluvium, even alopecia, except for exfoliative erythroderma syndrome (EES) arising in eczema or psoriasis.

NAILS Thickening of nail plates, onycholysis, and shedding of nails.

PIGMENTATION In chronic EES, there may be hyperpigmentation or patchy loss of pigment in patients whose normal skin is brown or black.

CHEMISTRY Low serum albumin and increase in gamma globulins; electrolyte imbalance; acute-phase proteins increased.

HEMATOLOGY Leukocytosis.

BACTERIAL CULTURESkin: Rule out secondary Staphylococcus aureus infection. Blood: Rule out sepsis.

DERMATOPATHOLOGY Depends on the type of underlying disease. In all, there is parakeratosis, inter- and intracellular edema, acanthosis with elongation of the rete ridges, exocytosis of cells, edema of the dermis, and an inflammatory infiltrate.

IMAGING In suspected paraneoplastic cases.

Diagnosis

The history of the preexisting dermatosis may be the only clue. Also, pathognomonic signs and symptoms of the preexisting dermatosis may help, for example, dusky-red color in psoriasis (Fig. 8-1) and yellowish red in pityriasis rubra pilaris (see Fig. 3-16); typical nail changes of psoriasis; lichenification, erosions, and excoriations in atopic dermatitis and eczema; diffuse, relatively nonscaling palmar hyperkeratoses with fissures in CTCL and pityriasis rubra pilaris; sharply demarcated patches of noninvolved skin within the erythroderma in pityriasis rubra pilaris; massive hyperkeratotic scale of scalp, usually without hair loss in psoriasis and with hair loss in CTCL and pityriasis rubra pilaris; in the latter and in CTCL, ectropion may occur.

Guarded, dependent on underlying etiology. Patients may succumb to infections or, if they have cardiac problems, to cardiac failure (high-output failure).

Supportive care, may require hospitalization. Warm and humid environment to prevent hypothermia. Discontinue all unnecessary medications.

TOPICAL Topical steroids, emollients.

SYSTEMIC Oral glucocorticoids for remission induction but not for maintenance. Antibiotics if there is bacteremia or septicemia. Antihistamines as needed for pruritus.