Skin-nontumor / Clinical dermatology
Other dermatoses
Seborrheic dermatitis

Author: Mowafak Hamodat, M.D., MB.CH.B, MSc., FRCPC (see Authors page)

Revised: 21 July 2016, last major update August 2011

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Seborrheic dermatitis [title]

Cite this page: Seborrheic dermatitis. PathologyOutlines.com website. http://pathologyoutlines.com/topic/skinnontumorseborrheicdermatitis.html. Accessed December 9th, 2016.
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's 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"
Treatment
  • Keratolytic agents, some over the counter
  • Anti-inflammatory products, such as topical corticosteroids, have some effect
Clinical Images

Images hosted on PathOut servers:

Breast skin, courtesy of Mark R. Wick, M.D.



Images hosted on other servers:

Redness (erythema) and mild scaling

Light pink papules

Micro 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
Micro Images

Images hosted on PathOut servers:

Breast skin, courtesy of Mark R. Wick, M.D.

Additional References