SD & AV Flashcards
Def of Seborrheic Dermatitis
- A common erythematous scaling eruption that is localized to the seborrheic sites.
Etiology of Seborrheic Dermatitis
Pityrosporum ovale may play a role.
Pathogenesis of Seborrheic Dermatitis
Prevalence of Seborrheic Dermatitis
eczematous form is estimated at 5%
Age affected by Seborrheic Dermatitis
- Usually begins in adolescence (9-11 years) (with puberty) peak at age 40
- Uncommon in preadolescent childhood (exclude t.capitis)
- Infantile SD
which sex is more commnly affected by Seborrheic Dermatitis?
More common in males than females. (M > F)
what are sites of Seborrheic Dermatitis?
- Scalp, behind ears, face
- Pre-sternal and interscapular areas
- flexures (umbilicus, axilla, infra-mammary, inguinal fold, perineum or anogenital crease.
Lesions of Seborrheic Dermatitis
- Scalp
- Ears
- Eyebrows & Beard
- Galbrous skin
- Nasolabial fold
- Eyelid margin
Scalp lesions of Seborrheic Dermatitis
- Non inflammatory (dandruff) (pityriasis capitis)
- Inflammatory (seborrheic eczema)
Shape of Non inflammatory
(dandruff) (pityriasis capitis) SD
Diffuse fine white (branny) or greasy scales
Characters of Non inflammatory
(dandruff) (pityriasis capitis) SD
what is the mildest form of SD?
Non inflammatory
(dandruff) (pityriasis capitis) SD
Characters of Inflammatory Scalp SD (seborrheic eczema)
SD in Ears
- retro-auricular scaling, crusting and fissuring.
Persistent non purulent otitis externa may occur.
SD in Eyebrows and beard
fine scaling
SD in Glabrous skin
diffuse redness.
SD in nasolabial fold
greasy scales.
SD in Eyelid margin
seborrheic blepharitis.
SD of facial skin
SD of trunk
Flexures (inverse SD) (axillae, groins, sub-mammary areas and umbilicus)
erythematous patches with maceration and oozing.
Types of inverse SD
- Scaling Intertrigo
- Non-Scaling Intertrigo
- Crusted Fissures
- Weeping Dermatitis
- Sebopsoriasis
Scaling intertrigo
- Sharply marginated erythema and greasy scaling
Non scaling intertrigo
May be erythema only
Weeping dermatilis
- Due to sweating, secondary infection, and inappropriate treatment,
- Erythema, maceration, oozing, crusting.
Sebopsoriasis
- features of both psoriasis and SD.
Severity varies from mild dandruff to exfoliative erythroderma
..
Examples of Extensive SD
- Erythrodermic: rare
- HIV infection
- Parkinson’s disease (with seborrhoea)
Adult SD
DDx of adult scalp SD
Introduction to TTT of SD
2 steps regimen in TTT of SD
Def of Infantile SD
- SD inearly infancy due to stimulation of sebaceous glands by maternalandroge
Charachters of Infantile SD
- simulates SD in adult, but the scaling on the scalp is thick forming yellowish heaped lesion (cradle cap).
Onset of Infantile SD
- Begins 2-8 weeks after birth
Healing of Infantile SD
- The lesions usually subside within 3-4 weeks.
- May persist for several months
CP od Infantile SD
TTT of Infantile SD
DDx of Scaly scalp in prepubertal children
Def of Acne Vulgaris
- Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous apparatus, characterized by formation of comedones.
Pathogenesis of Acne Vulgaris
4 major factors (multifactorial disorder) are involved in the pathogenesis of acne in the genetically predisposed person.
- Increased sebum secretion
- Hyperkeratosis of pilosebaceous duct
- Propionibacterium acne (P. acne) colonizes pilosebaceous duct
- Propionibacterium acne (P. acne) colonizes pilosebaceous duct
Increased sebum secreation
(Pathogenesis of Acne Vulgaris)
- which may result from increased local synthesis of androgen in sebaceous glands or increased response to it.
Hyperkeratosis of pilosebaceous duct (Pathogenesis of Acne Vulgaris)
Propionibacterium acne (P. acne) colonizes (Pathogenesis of Acne Vulgaris)
- Pilosebaceous duct and contributes in the formation of comedones and pustules.
Inflammation
(Pathogenesis of Acne Vulgaris)
initiated by P:acne
what causes Hyperkeratosis of pilosebaceous duct?
results from the irritant effect of excess sebum.
what does Obstruction of pilosebaceous duct result in?
result in comedones which consist of horny cells, sebum, and bacteria.
Types of comedoens according to level of obstruction
- If obstruction is deep: comedones are closed with narrow orifice (white head).
- If obstruction is superficial: the comedones are open and have a patulous orifice (black head).
what does Propionibacterium acne (P. acne) colonize?
pilosebaceous duct
what initiates inflammation in Acne Vulgaris?
P. acne
what are Micro-comedones?
Invisible hyperkeratotic plug made of sebum and keratin in follicular canal
Excerbating factors of Acne Vulgaris
Age of Acne Vulgaris
- Adolescence of both sexes. (12-24 years ) mainly
- May start at 10 years and persist up 50 years
Lesions in Acne Vulgaris
Characters of Closed Comedones
- Skin coloured
- No visible follicular opening.
- Often inconspicuous and require adequate lighting and stretching of the skin to be seen
Classification of Acne Vulgaris
1- Mild acne: comedones with little or no papules.
2- Moderate acne: comedones, papules and pustules.
3- Severe acne: nodules and cysts predominate.
Course of Acne Vulgaris
Sites of Acne Vulgaris
face, back, chest and shoulders.
TTT of Acne Vulgaris
Topical in TTT of Acne Vulgaris
- Comedolytic agents
- Antibacterial agents
Comedolytic agents in TTT of Acne Vulgaris
what is cornerstone in acne ttt?
Topical retinoids
AV = Acne Vulgaris
Topical retinoids in TTT of AV
Retinoic acid (0.05-0.1%) is used in gradually increasing concentration
SE of Topical retinoids in TTT of AV
It may cause dryness & irritant dermatitis. (Most common side effect)
what are examples of Topical Retinoids?
Antibacterial agents in TTT of AV
Characters of Benzoyl peroxide (BPO) (2.5, 5, 10)%
- no resistance has mild comedolytic effect.
- It may cause contact dermatitis.(irritant)
what are topical antibiotics used in TTT of AV?
erythromycin and clindamycin are effective in pustular lesions. (not alone)
Indication for topical TTT of AV
Systemic TTT of AV
- Antibiotics
- Antiandrogens
- Isotretinoin
- Dapsone
- Miscellanous therapy
- TTT of scars
what is the systemic antibiotic of choice in acne?
- Doxycycline: 100mg/day is the antibiotic of choice in acne.
- This dose is given until acne clears then dec. the dose gradually for 6 months
- Erythromycin and Azithromycin are good alternatives.
- clindamycin
MOA of antibiotics in systemic TTT of AV
- Reduce inflammation
- Reduce P: acne population> reducing bacterial production of inflammatory factors as FFA
- Intrinsic anti-inflammatory
- Reduce PMN (poly morphonuclear leukocytes) migration
Indication of using of antiandroges on TTT of AV
used only in females with severe nodulocystic acne
Examples of antiandroges used in TTT of AV
1- contraceptive as Yasmin
2- Cyproterone acetate (with OCPs diane)
3- Spironolactone (K sparing diuretic but has
antiandrogen effect)
Effects of isotretinoin used in systemic TTT of AV
- It decreases sebum secretion
- Decrease P. acne.
- Decrease follicular hyperkeratosis
- has anti-inflammatory effect
AE of isotretinoin used in systemic TTT of AV
It is teratogenic drug with serious side effects, so it should be used only in severe acne and by highly experienced dermatologists.
Dapsone Systemic TTT of AV
Anti-inflammatory drug used in severe acne with special precautions.
Miscellaneous therapy
Systemic TTT of AV
Comedonae removal:
- If comedones are resistant
intralesional steroids:
- Triamcinolone acetonide (2-5 mg/ml)
- Used for large inflammatory nodules/cysts
TTT of scars
Systemic TTT of AV
- Dermabrasion, laser resurfacing, deeper chemical peels
- Filler substances
- Punch excision (ice-pick) scar
Treatment according to the severity of acne can be given as follow (overview)
Def of Miliaria (Sweat rash)
A disorder of the sweat duct in which obstruction of the sweat ducts at various levels occurs in association with excessive sweating»_space; sweat retention
Etiology of Miliaria (Sweat rash)
Common in:
- Neonates: immature eccrine sweat ducts
- Adults: living in hot humid condition
Resolve in cool environment
Predisposing factors for Miliaria (Sweat rash)
1- Hot humid condition.
2- Excessive clothing.
3- Obesity.
4- Febrile illness.
Incidence of Miliaria (Sweat rash)
- The disease occurs in the tropics and subtropics
- Affects persons of all ages and both sexes.
Site & Size of lesion of Miliaria (Sweat rash)
- Any site
- Pin head size
Lesions of Miliaria (Sweat rash)
- The eruption consists of closely set red papules, vesicles
- It is associated with itching, prickling, or burning sensation.
- In infants the eruption may be generalized,
and it may occur in any season depending on the habits of overclothing.
Complications of Miliaria (Sweat rash)
impetigo, folliculitis, and boils.
Types of Miliaria (Sweat rash)
TTT of Miliaria (Sweat rash)
Stages of Hair growth
Causes of hair loss
- Physiological
- Pathological (Alopecia)
Definition of Alopecia
loss of hair from normally hairy area
Types of Alopecia
- Cicatricial or scarring alopecia (permanent)
- non Cicatricial or nonscarring (transient)
Causes of Non-cicatricial alopecia
- Conginetal
- Aquired
Aquired Causes of Non-cicatricial circuscribed (Patterned) alopecia
Aquired Causes of Non-cicatricial alopecia
- Circumscribed (Patterned)
- Diffuse
Aquired Causes of Non-cicatricial Diffuse alopecia
Congenital causes of cicatricial alopecia
developmental defect
Aquired causes of cicatricial alopecia
Definition of Alopecia Areata
circumscribed non scarring hair loss with normal skin
Etiology of Alopecia Areata
CP of Alopecia Areata
Lesions in Alopecia Areata
- Circumscribed area of hair loss, nonscarring with normal skin
- Positive exclamation mark! (tapered proximal end of the hair shaft)
- May affect scalp, face or body hair
Clinical types of Alopecia Areata
Prognosis of Alopecia Areata
Bad prognosis in the following conditions:
1- Alopecia totalis, universalis and ophiasis
2- Alopecia areata with nail pitting
3- Alopecia areata in atopics
Associated features to Alopecia Areata
1- Nail pitting
2- Atopy (atopic dermatitis)
3- Vitiligo
4- Cataract
DDx of Alopecia Areata
TTT of Alopecia Areata
Causes of hyperpigmentation
Causes of Hypopigmentation
Casues of depigmentation
Def of Vitiligo
acquired idiopathic depigmentation (leukoderma) of the skin
Etiology of Vitiligo
Precipitataing factors for Vitiligo
1- Emotional stress
2- Sun burn
3- Physical trauma (Koebner’s phenomenon)
CP of Vitiligo
- Milky white depigmented macules or patches affecting any area.
- Hair and mucous membranes may be affected
Sites: face, hand, feet. back are sires of predilection
Classification of Vitiligo
Prognosis of Vitiligo
1- Unpredictable
2- Stationary
3- Spontaneous re-pigmentation
4- Slowly progressive
5- Rapidly progressive
DDx of Vitiligo
1- Pityriasis alba
2- Pityriasis versicolor (hypopigmented type)
3- Post inflammatory hypopigmentation
4- Albinism
5- Post-burn and post-chemical depigmentation
TTT of Vitiligo