The prevalence has been estimated to be around 35 percent among patients with early HIV infection, and up to 85 percent among patients with AIDS Patients with Parkinson disease often have increased sebum production; in these patients seborrhea and seborrheic dermatitis improve with L-dopa therapyThe reason for the increased susceptibility of patients with HIV infection to seborrheic dermatitis is not known.
Malassezia hydrolyze human sebum, releasing a mixture of saturated and unsaturated fatty acids. They take up the required saturated FAs, leaving behind unsaturated FAs. The unsaturated FAs penetrate the stratum corneum and due to their non-uniform structure breach the skins barrier function. This barrier breach induces an irritation response, leading to dandruff and seborrheic dermatitis.The Malasseziaspp that have been most commonly associated with SD are M. globosa and M. restricta, both of which are commensal yeasts that require an exogenous source of lipids.
Spongiosis is mainly intercellular edema (abnormal accumulation of fluid) in the epidermis, and is characteristic of eczematous dermatitis, manifested clinically by intraepidermal vesicles (fluid-containing spaces),
Pimecrolimus belongs to a family of calcineurin inhibitors that affect T-cell activation, which is a critical step in the cascades inflammation involved in many skin disorders. There is also evidence to suggest that pimecrolimus has direct effects on the release of exogenous IL-2inhibition of pro-inflammatory mediators released from mast cells, such as histamine, serotonin, and B-hexosaminidaseblinded trial of patients with facial SD (N=40), 83 percent of patients achieved complete clearance after two weeks of twice-daily application of pimecrolimus 1% creamThis results in inhibition of T-cell activation, which causes downregulation of the release of proinflammatory cytokines without alteration of fibroblast activity or vasculature proliferation.11–13 Therefore, application of topical pimecrolimus does not cause dermal atrophy or telangiectasia formation.
Comprehensive overview of
further evidence showing the effectiveness and safety of pimecrolimus
Almansouri Daifallah MD
Investigation, and DDx,
Priscription table of 1st line medication dose
2 commonest and 2 most serious side effects:
Progression, severity and response assessment methods
• Seborrhoeic dermatitis (SD) is chronic-recurrent
common skin inflammation affect sebaceousgland-rich areas of skin causes scaling.
• Dandruff(pityriasis sicca): mildest form of
seborrhoeic dermatitis “scaling without
• Cradle cap “
” : is transient form of
seborrhoeic dermatitis affecting infants.
• SD may be presoriatic stage and may associated
with psoraisis and called “seborrhiasis”
• Seborrhic: adjective from “sebum” and means that the
disease particularly affects the sebaceous-gland-rich
areas of skin. But not caused by seborrhoea.
• Dermatitis: derma: skin, -itis: inflammation.
– French: dermatite séborrhéique
– Synonym: Dandruff(pityriasis sicca), cradle cap.
• Two peaks: infant after 2 wks + 20s -30s.
NB. The amount of
malassezia is not
•Helper T cells,
and antibody titers
This lipase hydrolyzes sebum TG into > unsaturated fatty acid
(non-uniform) > penetrating the skin cause > epidermal hyperprolifration (causes parakeratosis) and inflammation (causes
spongiosis) >flakes shedding , loss skin barrier function.
RESULT: Inflammation > pruritis. Hyperprolifration> flakes = SD
Summery of pathophysiology
• Malassezia ecosystem and interaction with
• Initiation and propagation of inflammation;
• Disruption of proliferation and differentiation
processes of the epidermis; and
• Physical and functional skin barrier disruption.
Classification: Body Folds
Description: diffuse, exudative,
sharply marinated, brightly
erythematous eruption; erosions
and fissures common.
Same as other areas but
Castellani's paint is very
I. Remove crust: salicylic acid, olive oil, coal tar
II. Ketoconazole 2% shampoo
If failed > Selenium sulphide shampoo 2.5% or ciclopirox 1%.
If no compliance > zinc pyrithione shampoo
If symptoms subside > continue: once week for 2 weeks.
III. Severe itching: potent steroid
betamethasone valerate 0.1%,
hydrocortisone butyrate 0.1%
mometasone furoate 0.1%.
Nb. Steroid not applied on bear.
IV. F/U not required unless complicated or resistant
Message for few Once daily
left on for five to Twice/week
Zinc + B6
Sick child or < 2yr
Safe for pregnant
Very safe, rarely;
Subside within 1st
Pregnancy; Cat C
Smear for bacteria
Response to Rosacea Tx
Mild psoriasis vulgaris
• Dandruff is desquamation without
• Tx: zinc pyrithione shampoo 1 to 2%.
• B6 or zinc oxide deficiency.
• Response assessment:
• Relapse is prevented by once/ week antifungal
• Flaking and pruritus are hallmark of SD.