Seborrheic Dermatitis Flashcards
Disease characteristic
erythematous, scaly, pruritic patches and plaques with a yellowish, greasy appearance
where do rashes tend to develop?
scalp
similar to dandruff in what ways?
- both cause white/yellow scales
- both can be dry or greasy
- both can be itchy
how to differentiate it from dandruff?
- SD develops more than just scalp (ears, eyebrows, beard, skin around nostrils, chest)
- inflammed
extensive SD can develop in
- armpits
- belly button
- groin
- buttocks
- under breasts
pathophsiology
unknown, but:
1. disruption of microbiata
2. impaired immune reaction to malassezia spp. associated with diminished T-cell response
3. increased presence of unsaturated fatty acids on skin surface
4. disruptoin of cutaneous NTs
5. abnormal sheddingof keratinocytes
6. epiermal barrier disturbancesassociated with genetic factors
Malassezia species
lipophilic yeast genus part of the normal flora of skin; most prevalent fungal genus on skin fo rhumans; pathogenic if invades the stratum corneum
in SD, inflamatory reaction seems to be that irritant non-immunogenic stimulatoin of the immune system increases in what 2 cells?
NK+, CD16 activation
Cradle cap
occurs in 2-12 months of age, appears on the scalp, folds of skin, chest, back, and diaper area, and usually goes away on its own within months
Adolescence SD
goes away without treatment, but also possible to have the disease for life and experience flare-ups
adulthood SD
usually 30s or later, especially common in ≥50 years
disease flare-ups are typically seasonal, most being in ___ and disappearing in ___
most in winter, disappearing in warm, humid weather. also occurs when stressed
SD worldwide prevalence
5%
groups more likely to develop
- Black people
- men > women
- people with psoriasis/rosacea (called sebopsoriasis if psoriasis and SD)
- certain medications
6 medications that increase the risk for SD
- Aranofin
- Fluoruracil
- Griseoulvin
- Haloperidol
- Lithium
- Psoralen/PUVA
