Dermatophatology part 5 Flashcards
Pempphigus vulgaris
most common and most severe type of pemphigus, 80% of cases
30-50 y.o., men and women
involves scalp, face, axillae, groin, trunk, points of pressure, oral ulcers
5-15% mortality
Pemphigus vulgaris path
IgG against desmogleins 1 and 3 in desmosomes in the suprabasal deep epidermis and mucosal epithelium
suprabasal split; acantholytic blisters
80-90% with oral lesions
general involvement with flaccid blisters which rupture leaving erosion with crust
psoitive nikolsky sign (pressure on blister caues later spread of lesion.)
pEMPHIGUS VULGARIS histo
acatholysis (lysis of intracellular adhesions connecting squamous epithelial cells)
single layer of intact basal cells forms the blister base (row of tombstones)
superficial lymphocytic inflammatory infiltrate in dermis
eosinophils may be seen within the dermal infiltrate
DIF: net like patter of intercellular IgG deposits
pemphigus vegetans
rare form
large moist verrucous, vegetating plaques rather than blisters
oral lesions common
assocaited with ulcerative colitis
pemphigus foliaceus
brazil and other geographic regions
taret Ag is Dsg1
subcorneal blister
Pempphigus tx
immunosuppressives and supportive
Bullous pemphigoid
elderly individuals
inner aspects of thigs, flexor surfaces of forearms, axillae, groin and lower abdomen
oral lesions in 10-15%, usually after cutaneous lesions
Bullous pemphigoid pathology etiology
targets BPAg1 and 2 in the hemidesmosomes (only BPAg2 is known to cause blisters)
subepidermal, nonacantholytic blisters
sturdy blisters (roof is full thickness of epidermis), usually 2 cm but up to 4-8 cm, do not ruputres as easily as pemphigus, without infection will heal without scarring
bullous pemphigoid histo
subepidermal, nonacantholytic blisters
early perivascular infiltrate of lymphocytes
eosinophils typically present in blister cavity
peripheral eosinophilia and elevated serum IgE often present
direct immuno fluorecence shows linear deposition of c3 and igG along dermoepidermal junction.
Dermatitis herpetiformis
Incidience is 39/100000
onset is 20-60 years with 2:1 M:F ration
etiology: IgA autoantibodies to transglutaminases bind to TG in gut and cross react with reticulin in fibrils in skin
associated with HLA B8, DR, DQ
Dermatitis herpetiforms Pathology etiology
IgA autoantibodies to transglutaminases which cross react with reticulin in the fibrils that anchor hemidesmosomes to the dermis
dermatitis herpetiformis gross
symmetrically grouped lesions
papules and plaques progressing to vesicles and bullae
buttocks, elbows, knees, scapular areas
very pruritic
Dermatitis herpetiforms associations
gluten sensitive enteropathy occurs in nearly all patients and must be demonstrated by small bowel biopsy
there may be no GI symptoms
Dermatitis herpetiformis histo
microabscesses at dermal papillae
Subepidermal blsiter
neutrophil microabscesses and fibrin depsotion in tips of dermal papillae
basal cells overlying tips show dermoepidermal separation eventually coalescing to form blister
direct immunofluorescence demosntrates discontinous granular deposition if IgA in tips of dermal papillae.
Dermatitis herpetiformis diagnosis
skin biopsy
antiendomysial antibodies (specific for TG)
endoscopy blunting of villi in small bowel
Dermatitis herpetiformis tx
gluten free diet: response is very slow\
dapsone: response within hours, check G6PD level, monitor methemoglobin and CBC levels
a chronic disease, 1/3 pts may have spontaneous remission
Epidermylysis bullosa
group of disorders caused by inherited defects in proteins that lend stability to the skin
at least ten genes have been implicated
common to all is tendency to form blisters at points of pressure, rubbing, trauma
sx at or soon after brith
Epidermolysis bullosa simplex type
mutations in either gene encoding keratin 14 or 5 which form a functional keratin fiber resulting in a basal cell layer defects
Epidermolysis bullosa: Jucntional type
blisters formed from separation of lamina lucida
Epidermolysis bullosa: Dystrophic types
blister below lamina densa, from defect in collagen VII, scar formation on healing
Epidermolysis bullosa: Non herlitz junctional
defect in laminin VB3
Epidermylysis bullosa: Histo
fibrin deposition in the floor of the blister cavity
some cases may show neutrophils within the papillary dermis, while other cases are histologically indistibguishable from bullous pemphigoid
dermal fibrosis (scar) may be present in the dermis
Prophyria cutanea tarda assocations
30-50 years, females on OCP, alcohol use, associated Hep C
Prophyria cutanea tarda etiology
uroporphyrinogen decarboyxlase (UROD deficiency > excessive accumulation of porphyrins
Prophyria cutanea tarda Type 1
acquired by exposure to drugs/chemicals, hepatic UROD is inhibited
Prophyria cutanea tarda Type 2
Autosomal dominant, deficient in RBCs and fibroblasts
Porphyria cutanea Tarda gross and sx
porphyrins make skin photosensitive
tense subepidermal bulla on normal appearing skin in sun expsoed areas
may also get hypertrichosis on face
exacerbated by iron; alcohol; smoking; estrogens; hepatitis C; HIV; halogenated hydrocarbons
Prophyria cutanea tarda: Diagnosis
test for increased uroporphyrin in urine, will fluoresce orange under wood’s lamp
Porphyria cutanea tarda: TX
avoid alcohol, estrogens, fungicides
phlebotomy to reduce iron stores
low dose of chloroquine if low Hgb
Prophyria cutanea tarda histology
subepidermal vesiculation
acral skin with compact orthokeratosis
solar elastosis (due to patient age and characteristics acral location)
minimal inflammatory infiltrate
protuberance of rigid dermal papillae into blister cavity (festooning)
thickening of walls of superficial dermal vessels
Acne vulgaris
may begin as early as 9-11 years old
may continue into 3rd and 4th decade of life
Most patients have both obstructive and inflammatory lesions
distribution is on face, chest, and upper back
Acne vulgaris: pathogenesis
obstruction of sebaceous follicles by sebum promotes proliferation of propionibacterium acnes (anaerobe)
Obstructive acne: Closed comedones
whiteheads. flesh colored dome shaped papules
Obstructive acne: Open comedones
blackheads. Dilated pore filled with keratinous material (not dirt)
Inflammatory acne
lesions progress from papules/pustules to nodules to cysts
Acne vulgaris risk factors
male sex
puberty
cushing’s syndrome
oily complexion
androgen excess
eating chocolate and fatty foods does not worsen acne
ACne vulagaris histology
keratinization of lower portion of the follicular infundibul;um with development of keratin plug blocking outflow of sebum to skin surface
hyperatrophy of sebaceous glands with puberty (or increased hormonal stimulation)
lipase synthesizing bacter (propiuonibacterium acnes) colonizing the upper and midportion of the hair follicle converting lipids within sebum to proinflammatory fatty acids
inflammation of the folice associated with release of cytotoxic and chemotactic factors
Acne vulgaris tx
start with 1 drug and then add to regimen if no improvement within 6 weeks
- topical bezoyl peroxide- destroys bacteria and dries skin
- topical retinoids: causes peeling of skin which prevents pore clogging, good for comedonal acne (tretinoin, adapalene, tazarotene)
- topical erythromycin or clindamycin: suppress P. acnes.
- systemic antibiotics: tetracyclines, erythromycin, clindamycin, bactrim
- Oral retinoids: for severe cystic acne unresponsive to the above treatments. (teratogen)
Some oral contraceptive may improve patient’s acne
ACne rosacea
4 stages
- flushign episodes (pre rosacea)
- Persisten erythema and telangeictasias
- Pustules and papules
- Rhinophyma: skin on nose becomes thick and greasy, hyperplasia of sebaceous glands, connective tissue and vasculature. (Nose)
comedoens are not found
affect nose and cheeks including nasolabial folds
Acne rosacea tx
diagnosis si made clinically
avoid alcoholic and hot bevarages, extremes of temperature and emotional stressors
treat long term with topical metronidazole gel and oral doxycycline
Rosacea histo
perfollicular infiltrate of lymphocytes
surrounded by ermal edema and telangiectasia
rhinophyma: hypertrophy of sebaceous glands
and follicular plugging by keratotic debris
