Erytheme

Erytheme is a term occasionally used in dermatology to describe redness of the skin that results from dilatation of superficial cutaneous blood vessels. In many modern sources, erytheme is treated as largely synonymous with erythema, with the key distinction being that erythema denotes the observable redness and erytheme is an older or less commonly used label for the same phenomenon. Clinicians typically prefer the term erythema or specify the pattern of redness, such as diffuse erythema, focal erythema, or erythroderma.

Redness associated with erytheme can vary in appearance and is often accompanied by warmth, and sometimes itching or pain. The redness typically blanches on pressure if the vessels are dilated but not permanently damaged. Patterns may be macular (flat) or patchy, and can be transient or persistent depending on the underlying cause.

Causes of erytheme include inflammatory skin conditions (for example dermatitis or eczema), infections (such as cellulitis or candidal dermatitis), physical or chemical irritation, sun and heat exposure, drug reactions, and certain systemic diseases that affect blood flow or inflammatory status. Physiologic flushing during exercise or emotional stress can also produce temporary erytheme.

Diagnosis is usually clinical, based on visual inspection and history. In unclear cases, clinicians may investigate for infection, allergy, or systemic disease, and may perform skin sampling or laboratory tests to determine the underlying cause.

Treatment focuses on addressing the underlying cause. General measures include protecting the skin, avoiding irritants, and using targeted therapies for inflammation or infection as appropriate. Prognosis depends on the etiology; most superficial erytheme improves with treatment or resolution of the trigger.