Erythroderma

• Generalized blanchable redness of the skin that may be associated with desquamation.
• Desquamation is a normal process in which the cornified (outermost) layer of the epidermis is sloughed in fine scales or sheets.
• Erythema and erythroderma will blanch because the color (“redness”) is due to increased blood flow, not leakage of blood into the skin, as in purpura.

• 

  Erythroderma with "skip areas" of normal skin in a patient with pityriasis rubra pilaris.

• 

  Erythroderma with exfoliation in a child with infantile psoriasis.

• 

  Diffuse erythema of the legs and feet in erythroderma induced by a medication.

• 

  Erythrodermic psoriasis presenting with widespread erythematous and hyperpigmented plaques.