Seborrheic dermatitis is a chronic inflammatory disorder affecting areas of the head and trunk where sebaceous glands are most prominent. Lipophilic yeasts of the Malassezia genus, as well as genetic, environmental and general health factors, contribute to this disorder. Scalp seborrhea varies from mild dandruff to dense, diffuse, adherent scale. Facial and trunk seborrhea is characterized by powdery or greasy scale in skin folds and along hair margins. Treatment options include application of selenium sulfide, pyrithione zinc or ketoconazole-containing shampoos, topical ketoconazole cream or terbinafine solution, topical sodium sulfacetamide and topical corticosteroids. (Am Fam Physician 2000;61:2703-10,2713-4.)
The etiology of seborrheic dermatitis remains unknown, although many factors, including hormonal, have been implicated. This chronic inflammatory skin disorder is generally confined to areas of the head and trunk where sebaceous glands are most prominent. When seborrheic dermatitis occurs in the neonatal period, it usually disappears by six to 12 months of age, suggesting that it may be a response to maternal hormone stimulation.1
Seborrheic dermatitis frequently affects persons in postpuberty. Additional evidence of hormonal influence is provided by research demonstrating that the human sebocyte responds to androgen stimulation.2
Pityrosporum ovale, a lipophilic yeast of the Malassezia genus, has been implicated in the development of this condition.3 It has been suggested that seborrheic dermatitis is an inflammatory response to this organism, but this remains to be proved.4 P. ovale is present on all persons. Why some persons develop seborrheic dermatitis and others do not is unclear. The colonization rate of involved skin by this organism may be lower than that of uninvolved skin.3 Nonetheless, the fact that seborrheic dermatitis responds to antifungal medications is strongly suggestive of the role of yeast in this disorder.
for more.........
http://www.aafp.org/afp/20000501/2703.html
Pityrosporum ovale, a lipophilic yeast of the Malassezia genus, has been implicated in the development of this condition.3 It has been suggested that seborrheic dermatitis is an inflammatory response to this organism, but this remains to be proved.4 P. ovale is present on all persons. Why some persons develop seborrheic dermatitis and others do not is unclear. The colonization rate of involved skin by this organism may be lower than that of uninvolved skin.3 Nonetheless, the fact that seborrheic dermatitis responds to antifungal medications is strongly suggestive of the role of yeast in this disorder.
for more.........
http://www.aafp.org/afp/20000501/2703.html
Comments