Seborrhoeic Dermatitis Flashcards
Clinical features
Puberty throughout adult life
Asymtomatic vs Variable itch
Symptoms may be dispropionate to the clinical signs esp on scalp
Chronic relapsing course
Commensal lipophilic yeasts —> Malassezia (previously known as pityrosporum)
Areas with high density of sebaceous glands
- Scalp
- Face
- Central chest
- Anogenital areas
Localised Erythematous patches with superficial fine scaling
Predilection for skin folds including large flexures, submammary areas
Symmetrical distribution
Hypopigmentation may be prominent feature in dark skinned ppl
SCALP/BEARD
Mild flaking without underlying erythema vs more inflammatory with thicker, yellow, greasy scales and crusts
FACE Nasolabial folds Alar creases Nasal sidewalls Ear creases External ear canal/otitis externa Glabellar area Medial eyebrows Eyelids
Secondary bacterial or candida infection
EYELID
Anterior blepharitis (inflam,ation of the anterior eyelid margin)
- Flaky debris on the eyelashes near the base
- Conjunctival irritation amd red eye (when loose debris falls into eye)
PRESTERNAL
Localised Petaloid (petal-shaped) lesions
Can be widespread —> extend to uoper back, umbilicus, axillae, groin, submammary
LARGE FLEXURES (axillae, groin) Glazed and pink
Secondary infection with bacteria or candida
ANOGENITAL
INFANTILE VARIANT
Cradle cap and/or napkin dermatitis
Controversy if Variant of atopic eczema and psoriasiform napkin dermatitis
Additional involvement that helps to distinguish from atopic eczema -
- Eyebrows
- Paranasal areas
- Large flexures
By age 3 months of age
Disappears spontaneously by 8 months of age
Associated diseases
IMMUNOSUPPRESSION
HIV
- Occurs early in HIV infection —> initial clinical marker
- Immune reconstitution syndrome in HIV patients starting HAART
HTLV-1
IATROGENIC IMMUNOSUPPRESSION
renal transplant
CHRONIC NEUROLOGICAL DISEASE
Parkinsons disease
Spinal cord injury
HEREDITARY/GENETIC
Down syndrome
PSYCHIATRIC Depression Anxiety Anorexia nervosa Alcoholism
METABOLIC
HTN
Higher body fat content
Pathogenesis
Malassezia yeasts
M. Globosa M. Restricta M. Sympodialis M. Furfur M. Sloofiae
Normal skin microbiome/commensals
Reason for disturbance of symbiosis/balance unclear
Infundibulum of sebaceous glands —> lipids freely available
Epidermal barrier impairment
Pro-inflammatory cytokine production
Environmental factors
More common in winter
Improve with sun exposure
UV induced immunosuppression
DDx adult seb derm
Drug eruption Captopril Penicillamine Gold Lithium Cimetidine Interferon Erlotinib (EGFRi) Sorafenib/sunitinib Vemurafenib (BRAFi)
SCALP Psoriasis (more circumscribed, thicker, silvery scale) —> examine also for nail changes and other psoriasis plaques Sebopsoriasis (psoriasiform scaling in a seb derm distribution) —> non-defined entity ACD —> APT in atypical cases
FACE ACD —> APT in atypical cases and those with eyelid dermatitis Perioral dermatitis (involvement of skin below lateral lower lips, small papules, diamond shaped distribution) Pemphigus foliaceus —> skin bx, DIF if dx uncertainty Pemphigus erythematosus —> skin bx, DIF if dx uncertainty
TORSO
Pemphigus foliaceus —> skin bx, DIF if dx uncertainty
Pemphigus erythematosus —> skin bx, DIF if dx uncertainty
Pityriasis rosea mimics pityriasiform variant of seb derm (herald patch)
Early CTCL
LARGE FLEXURES (AXILLAE, GROIN)
Hailey hailey disease —> skin bx if suspicious
Darier disease (dome shaped papules) —> skin bx if suspicious
Erythrasma
DDx infantile seb derm
LCH
Zinc deficiency
Acrodermatitis enteropathica
IF SCALP ONLY
Tinea capitis
Pediculosis
Ix
Clinical dx
Dermoscopy scalp
Seb derm
- Arborising vessels
- Atypical vessels
Psoriasis
- Red dots amd globules
HIV testing
Mx
No definitive cure
May require long term maintenance treatment
Usually topicals - Topical azoles mainstay of Rx Topical terbinafine may be helpful Topical Ciclopirox Topical zinc pyrithione Topical coal tar Topical selenium sulphide Topical lithium gluconate Topical 4% nicotinamide (face) - helpful in co-exist acne/rosacea Topical 0.75% metronidazole gel (face) - helpful in co-exist acne/rosacea
for additional anti-inflammatory effects than antifungal monotherapy -
mild TCS
Calcineurin inhibitors o.e. Pimecrolimus, tacrolimus
Some strains of malassezia i.e. M globosa, M. Restricta resistant to azole antifungals —> Rx failure
PDT for seb derm and acne
Systemic Rx rarely indicated for recalcitrant/widespread seb derm
Itraconazole including pulse regimen
Mx scalp and beard seb derm
FIRST LINE
2% ketoconazole shampoo
Selenium sulphide shampoo
2 x per week for 1 month
Then 1-2 x per week for symptoms control
SECOND LINE
Zinc pyrithione shampoo
Coal tar shampoo
Salicylic acid shampoo
ADDITIONAL RX To remove scale/crust -
Topical keratolytic i.e. LPC/SA
Mineral/olive oil
ADDITIONAL RX for Severe scalp itch
Potent TCS i.e. Novasone, Clovex for 4 weeks
Mx face and body seb derm (adults)
FIRST LINE 2% ketoconazole cream OD/BD 1% Econazole cream BD 2% miconazole cream BD Clotrimoxazole cream BD/TDS
For at least 4 weeks then less frequently
SECOND LINE
Mild TCS for 1-2 weeks
ADDITIONAL RX for body
2% ketoconazole shampoo as a body wash
ADDITIONAL RX for eyelid involvement
Hygiene measures using cotton buds moitened with baby shampoo
Mx severe seb derm
Review Dx
HIV testing
Consider specialist referral
Mx infantile seb derm
FIRST LINE
Remove scalp crusts with baby shampoo and gentle brushing
+/- Overnight soak using WSP or warmed vegetable oil
Daily bathing with soap free wash
SECOND LINE
1% clotrimoxazole cream BD/TDS
1% econazole cream BD
2% miconazole cream BD
ADDITIONAL RX for nappy rash
TCS in selected cases (not routinely advised)
