title: Quantitative microbiology of the scalp in non-dandruff, dandruff, and seborrheic dermatitis.
abstract: The composition of the scalp microflora was assessed quantitatively in normal individuals and in patients with dandruff and seborrheic dermatitis, disorders characterized by increasing scaling. Three organisms were constantly found: (1) Pityrosporum, (2) aerobic cocci, and (3) Corynebacterium acnes. Pityrosporum (mainly Pityrosporum ovale) made up 46% of the total microflora in normals, 74% in dandruff, and 83% in seborvheic dermatitis. The geometric mean number of organisms per cm-2 in non-dandruff subjects was 5.04 times 10-5; 9.22 times 10-5 in dandruff subjects; and 6.45 times 10-5 in those with seborrheic dermatitis. The cocci were dominantly Baird-Parker type SII and no quantitative or qualitative change occurred in the scaling disorders. C. acnes comprised 26% of the flora on the normal scalp, 6% in dandruff, and only 1% in seborrheic dermatitis. These results differ significantly from previous reports which describe a much more complex microflora and suggest an etiologic role for microorganisms in dandruff.
mesh_terms: D016782:Apicomplexa / Q000302:isolation & purification; D001419:Bacteria / Q000302:isolation & purification; D001431:Bacteriological Techniques; D002374:Catalase / Q000032:analysis; D003030:Coagulase / Q000032:analysis; D012628:Dermatitis, Seborrheic / Q000382:microbiology*; D003902:Detergents; D005260:Female; D006801:Humans; D008290:Malassezia / Q000302:isolation & purification; D008297:Male; D010101:Oxygen Consumption; D011425:Propionibacterium acnes / Q000302:isolation & purification; D012535:Scalp / Q000166:cytology / Q000382:microbiology*; D012536:Scalp Dermatoses / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification; D015003:Yeasts / Q000302:isolation & purification
chemical_list: D003030:Coagulase; D003902:Detergents; D002374:Catalase