Skin nontumor

Spongiotic, psoriasiform and pustular reaction patterns

Seborrheic dermatitis

Last author update: 1 August 2011
Last staff update: 9 November 2020

Copyright: 2002-2023,, Inc.

PubMed Search: Seborrheic dermatitis [title]

Mowafak Hamodat, M.B.Ch.B., M.Sc.
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Cite this page: Hamodat M. Seborrheic dermatitis. website. Accessed October 4th, 2023.
Definition / general
  • Nummular eczema (silver dollar sized patches) to generalized exfoliative dermatitis (severe atopic dermatitis) to large vesicles on palms and soles (dyshidrosis)
  • Not due to any known agents, although associated with irritant contact dermatitis
  • One of the most common cutaneous manifestations of AIDS, affecting 20 - 80%
  • Also associated with Parkinson's disease, epilepsy, congestive heart failure, obesity, chronic alcoholism, Leiner disease (exfoliative dermatitis of infancy) and zinc deficiency
  • May occur as reaction to arsenic, gold, chlorpromazine, methyldopa and cimetidine
Clinical features
  • Erythematous scaling papules and plaques, sometimes with a greasy yellow appearance, with a characteristic distribution on scalp, ears, eyebrows, eyelid margin, and nasolabial area - the so called seborrheic areas
  • Keratolytic agents, some over the counter
  • Anti-inflammatory products, such as topical corticosteroids, have some effect
Clinical images

Contributed by Mark R. Wick, M.D.

Breast skin

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Redness (erythema) and mild scaling

Microscopic (histologic) description
  • Acute, subacute or chronic spongiotic dermatitis
  • In acute lesions, there is focal, usually mild, spongiosis with overlying scale crust containing a few neutrophils; the crust is often centered on a follicle; papillary dermis is mildly edematous; blood vessels in superficial vascular plexus are dilated and there is mild superficial perivascular infiltrate of lymphocytes, histiocytes and occasional neutrophils; some exocytosis of inflammatory cells but not as prominent as in nummular dermatitis
  • In subacute lesions, there is also psoriasiform hyperplasia, initially slight, with mild spongiosis and the other changes already mentioned; numerous yeast-like organisms can usually be found in the surface keratin
  • Chronic lesions show more pronounced psoriasiform hyperplasia and only minimal spongiosis; sometimes the differentiation from psoriasis can be difficult but the presence of scale crusts in a folliculocentric distribution favors seborrheic dermatitis
Microscopic (histologic) images

Contributed by Mark R. Wick, M.D.

Breast skin

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