Erythroderma is the term used to describe intense and usually widespread reddening of the skin due to inflammatory skin disease. It often precedes or is associated with exfoliation (skin peeling off in scales or layers), when it may also be known as exfoliativedermatitis (ED).
Erythroderma is rare. It can arise at any age and in people of all races. It is about 3 times more common in males than in females. Most have a pre-existing skin disease or a systemic condition known to be associated with erythroderma. About 30% of cases of erythroderma are idiopathic.
Erythrodermic atopic dermatitis most often affects children and young adults, but other forms of erythroderma are more common in middle-aged and elderly people.
The most common skin conditions to cause erythroderma are:
Drug eruption — with numerous diverse drugs implicated (list of drugs)
It is not known why some skin diseases in some people progress to erythroderma. The pathogenesis is complicated, involving keratinocytes and lymphocytes, and their interaction with adhesionmolecules and cytokines. The result is a dramatic increase in turnover of epidermal cells.
Systemic symptoms may be due to the erythroderma or to its cause.
Lymphadenopathy, hepatosplenomegaly, abnormal liver dysfunction and fever may suggest a drug hypersensitivity syndrome or malignancy.
Leg oedema may be due to inflamed skin, high output cardiac failure and/or hypoalbuminaemia.
Complications of erythroderma
Erythroderma often results in acute and chronic local and systemic complications. The patient is unwell with temperature dysregulation and losing a great deal of fluid by transpiration through the skin.
Heat loss leads to hypothermia.
Fluid loss leads to electrolyte abnormalities and dehydration.
Proteins may reveal hypoalbuminaemia and abnormal liver function.
Polyclonal gamma globulins are common, and raised immunoglobulin E (IgE) is typical of idiopathic erythroderma.
Skin biopsies from several sites may be taken if the cause is unknown. They tend to show nonspecific inflammation on histopathology. Diagnostic features may also be present.
Erythroderma is potentially serious, even life-threatening, and the patient may require hospitalisation for monitoring and to restore fluid and electrolyte balance, circulatory status, and body temperature.
People with known drug allergy should be made aware that they should avoid the drug forever, and if their reaction was severe, wear a drug alert bracelet. All medical records should be updated if there is an adverse reaction to a medication and referred to whenever starting a new drug.
Patients with severe skin diseases should be informed if they are at known risk of erythroderma. They should be educated about the risks of recurrence should they discontinue their medication.
What is the outlook for erythroderma?
Prognosis of erythroderma depends on the underlying disease process. If the cause can be removed or corrected, the prognosis is generally good.
If erythroderma is the result of a generalised spread of a primary skin disorder such as psoriasis or dermatitis, it usually clears with appropriate treatment of the skin disease but may recur at any time.
The course of idiopathic erythroderma is unpredictable. It may persist for a long time with periods of acute exacerbation.
References
Textbook of Dermatology. Ed Rook A, Wilkinson DS, Ebling FJB, Champion RH, Burton JL. Fourth edition. Blackwell Scientific Publications.
Okoduwa C, Lambert WC, Schwartz RA, et al. Erythroderma: review of a potentially life-threatening dermatosis. Indian Journal of Dermatology. 2009;54(1):1–6. doi:10.4103/0019-5154.48976. PubMed Central