Bullae and Desquamation Disorders Flashcards
structures that work to adhere cells to one another
Desmosomes
proteins inside desmosomes to allow for normal desmosome formation
Desmogleins
what holds the epidermis together?
Hemidesmosomes join cells of the epidermal basement membrane to the basilar membrane
- Autoimmune disorder
- Loss of cell to cell adhesion in the epidermis
- circulating antibodies of IgG that bind to desmogleins transmembrane glycoproteins in the desmosomes
- Autoantibodies interfere with adhesion = acantholysis
pemphigus
2 types of pemphigus
- Pemphigus Vulgaris: flaccid blisters on skin and erosions on mucous membranes
- Pemphigus Foliaceus: scaly and crusted skin lesions
pemphigus MC in who?
- Pemphigus Vulgaris - jewish/mediterranean
- Pemphigus Foliaceus - brazil
- 40-60 years old
- M:F = incidence
- Vesicles and bullae w/ serous content
- Flaccid/easily ruptured weeping
- Arising on normal skin
- Scattered & discrete - Localized or generalized with random pattern; Extensive erosions = bleed easily
- Nikolsky Sign
pemphigus
Dislodging or normal appearing epidermis by lateral finger pressure in the vicinity of lesions
Pressure on bulla = lateral extension
what is this sign?
MC areas?
Nikolsky Sign
- Scalp
- Face
- Chest
- Axillae
- Groin
- Umbilicus
s/s of pemphigus vulgaris
- Starts in oral mucosa
- Months may elapse before actual skin lesions
- burning/pain, No pruritus
- Painful mouth lesions = inadequate food intake
- Epistaxis
- Hoarseness
- Dysphagia
- Weakness
- Malaise
- Weight loss
s/s of pemphigus foliaceus
- No mucosal involvement
- Cutaneous lesions
- initial lesions: flaccid bullae, quickly ruptures, leaving superficial erosion
- MC sites: face, scalp, upper chest, abdomen
w/u for pemphigus
-
bx of edge of blister: (+) deposits of IgG
- Direct immunofluorescence (IF) staining: IgG and C3 deposited in lesional and paralesional skin; performed on normal-appearing skin adjacent to a lesion - ELISA for IgG ab to desmogelin 1 & 2
- PF +a-Dsg1
- PF + a-Dsg3 and Dsg 1
tx for pemphigus
- prednisone until no new blisters or nikolsky
- Concomitant Immunosuppressive: azathioprine / mycophenolate mofetil (Cellcept)
- wound care: wet compressions, routine bathing, anticipate infection
complications of pemphigus
- Fluid and electrolyte imbalances
- Secondary bacterial infections
- Osteoporosis - Calcium/Vit D supplementation
- Rare autoimmune disease MC in elderly pts (60-80)
- Interaction of autoantibody with BP antigen
- MC bullous autoimmune disease
bullous pemphigoid
pathophys of bullous pemphigoid
- BPAG1 & BPAG2 In hemidesmosomes of basal keratinocytes
- Followed by complement and mast cell activation, attraction of neutrophils and eosinophils, release multiple bioactive molecules from inflammatory cells
- Prodrome (weeks - months): Pruritus, Urticaria and papular lesions
- large, tense, firm-topped bullae
- serous or hemorrhagic fluid
- painful erosions after rupture
- (-) Nikolsky
- MC sites: axilla, medial thigh, groin, abdomen, ventral forearm, lower legs
- Oral lesions: less severe and less painful than pemphigus
bullous pemphigoid
w/u for bullous pemphigoid and findings
-
Bx (Gold Standard): Linear IgG deposits along basement membrane
- Perilesional skin
- C3 may occur in absence of IgG - DIF study: IgG ab present in 70% of pts
- ELISA - BPAG1 and BPAG2
- highly sensitive and specific
- few labs perform this test
tx for bullous pemphigoid
- refer
- prednisone
- +/- azathioprine
- +/- topical steroids
complications of bullous pemphigoid
- Fluid and electrolyte imbalances
- Secondary bacterial infections
- Osteoporosis - Calcium/Vit D supplementation
Acute hypersensitivity reaction affecting the skin and mucous membranes
Sometimes eye involvement
erythema multiforme
causes of erythema multiforme? which is MC?
- HSV (MC)
- Mycoplasma
- Sulfonamides
- PCN
- Allopurinol
- Barbiturates
- Phenytoin
- Phenylbutazone
s/s of erythema multiforme
- Erythematous, papular, or urticarial type lesion
- May precede bullae formation by months
- Bullae small or large
- Tense, firm topped oval or round
- on normal, erythematous, or urticarial skin: serous / hemorrhagic; Localized / generalized; Pruritic and painful - Mucosal Lesions: Erosions and ulcerations
- Lips, oropharynx, nasal, conjunctival, vulvar, anal; Eyes- corneal ulcer, anterior uveitis - Fever, weakness, malaise, and fatigue
- bilateral and symmetrical
Minor EM presentation
- Little - no mucosal involvement
- (+) vesicle, (-) bullae
- no systemic symptoms
- confined to extremities & face
Major EM presentation
- mucosal involvement
- confluence of lesions
- (+) Nikolsky sign
- (+) constitutional symptoms
- cheilitis/stomatitis
- vulvitis/balanitis
- eye involvement
- MCC - drug reaction
mgmt for EM minor
- self limiting - remove underlying cause if applicable
- antihistamines for pruritus
- topical steroids: low dose - face/intertriginous; medium dose trunk/extremities
- antivirals if needed
- painful oral lesions:
- high dose fluocinonide 0.05% gel 2-3x/d
- throat Soothie/Magic Swizzle
ingredients for throat smoothie/magic swizzle
- 1:1 of lidocaine viscous
- diphenhydramine (Benadryl)
- magnesium hydroxide (Maalox)
- +/- dexamethasone
1 tsp swish, gargle and spit/swallow q6h prn
tx for EM major
- DC offending agent/tx HSV if indicated
- Mucocutaneous lesions
- IV fluids if needed
- Throat Soothie/Magic Swizzle
- high dose PO prednisone
- Oral/parenteral pain control
- Wet compresses w/ Burow’s solution for large erosions - Ocular involvement- Immediate referral/consult ophthalmology
tx and complications of recurrent EM
- Daily prophylactic antiviral therapy
- Complications: Secondary bacterial infection; Fluid/electrolyte imbalances
Cytotoxic event caused by an immune response results in destruction of keratinocytes
SJS & TEN
causes of SJS & TEN
- MC drugs
- Chemicals
- Mycoplasma
- Viral infections
- Immunization
s/s SJS/TEN
- Fever, Chills, Malaise
- Headache, Sore throat, N/V/D
- Skin tenderness
- Abrupt onset of lesions
- Macule, papule, central vesicle/bullae, erosions
- Target lesion = 2 zones of color
- Rapid confluence
- +Nikolsky sign
- Trauma - full thickness epidermal detachment: Red, oozing dermis - distribution: Face and extremities - generalized
- Mucosal findings: Very painful, erythematous, erosions
- Lips, Buccal mucosa, Conjunctiva, Genitalia, Anal region - Eyes: Conjunctivitis, Keratitis, Synechia of the lid and conjunctiva
- Hair and nail: Loss of lashes and nails (TEN)
when is SJS/TEN an emergency?
Systemic symptoms: Fever, HR >120 (Sloughing of epidermis)
w/u and classification of SJS/TEN
- clinically
- Classification:
- SJS = < 10% body surface
- SJS/TEN = 10-30%
- TEN = > 30% - bx will aid
tx for SJS/TEN
- d/c offending agent
- IV Fluids
- Parenteral nutrition
- IV Pain meds
- Wound care: Wet dressing with burow’s solution; Non adherent dressing; Eye- saline and erythromycin ointment
- IV Steroids/IVIG = early
