Blisters Flashcards
What are the major bullous diseases
Pemphigus foliaceous: all ages, red/crusting, few fragile blisters, can be associated with SLE (pemphigus erythematosus), can be drug induced
Pemphigus: elderly, oral lesions, esophageal erosions, flaccid blisters, non-itchy, + Nikolsky’s, paraneoplastic variant
Cicatricial pemphigoid: elderly, itch, oral and eye involvement, few tense blisters on face and neck, heals with scar
Pemphigoid: elderly, itchy, uritcarial plaques, tense blisters, palms and soles
Dermatitis herpetiformis: middle age, very itchy, gluten-sensitive enteropathy, small bowel lymphoma
What diseases target the granular layer
Bullous ichthyosiform erythroderma
pemphigus foliaceus and erythematosus
What diseases target the upper and mid spinous layer
Dermatophyte infxn Dyshidrosis eczematous blister friction blister insect bite and scabies miliaria rubra viral blisters
What diseases target the basal layer
Erythema multiforme (epidermal type) Epidermolysis bullosa simplex fixed drug eruption kerosene necrosis lichen planus TEN
What diseases target the lamina lucida layer
BP Cicatricial pemphigoid DH Epidermolysis bullosa acquisita/letalis herpes gestationis suction blister thermal lesions
What diseases target the basal lamina and sublaminar connective tissue layer
Bullous dermatosis of hemodialysis bullous eruption of SLE Epidermolysis bullosa dystrophica Erythema multiforme (dermal type) Ischemic bullae (drug overdose) Lichen sclerosus et atrophicus porphyria cutanea tarda
What diseases target the subcorneal layer
Candida impetigo miliaria crystallina SSSS subcorneal pustular dermatosis
What diseases target the lower spinous layer
Benign familial chronic pemphigus
keratosis follicularis
pemphigus vulgaris
transient acantholytic dermatosis
Target molecule in Pemphigus vulgaris
Desmoglein 3 and 1
Target molecule in Pemphigus foliaceous
Desmoglein 1
Target molecule in Paraneoplastic pemphigus
Desmoglein 3, desmoplakin 1 and 2, BP230, envoplakin, periplakin, and others
Target molecule in IgA Pemphigus
Desmocollin 1
Target molecule in BP
BP180, 230 (hemidesmosome and lamina lucida)
Target molecule in Herpes gestationis
BP180, 230 (hemidesmosome and lamina lucida)
Target molecule in Cicatricial pemphigoid
BP180, laminin V (hemidesmosome and lamina lucida)
Target molecule in Epidermolysis bullosa acquisita
Type VII collagen (anchoring fibrils)
Target molecule in Linear IgA
LAD antigen (BP180) (hemidesmosome and lamina lucida)
Target molecule in Bullous SLE
Type VII collagen (anchoring fibrils)
Target molecule in dermatitis herpetiformis
unknown
Biopsy work up for blisitering disorders
Take one from the edge of a fresh lesion and one from normal, non-edematous skin
What disease process would you want to take a biopsy of the actual lesion (not edge) to perform DIF on?
HSP and vasculitis lesions
Dermatitis herpetiformis clinical presentation
usually in 2nd-5th decade
usually in caucasian patients
intensely burning urticarial papules, vesicles symmetrically distributed across extensor surfaces, scalp, and buttocks
DDx of DH
bullous erythema multiforme and bullous pemphigoid
Associated diseases in DH
Celiac disease
thyroid dysfunction
Linear IgA bullous dermatosis clinical presentation
May look like DH, BP, or cicatricial pemhigoid
Etiology of Linear IgA bullous dermatosis
Medications such as vancomycin (within 1-15 days after first dose)
Histology of DH
IgA deposits in upper dermis
- also see antibodies against epidermal transglutaminase 1 on Indirect immunoflorescence/ELISA
Histology for Linear IgA
IgA linear across basement membrane zone
How many DH patients have the gluten sensitive enteropathy
majority (there is a direct correlation between IgA anti-endomysial antibodies and the severity of gluten induced jejunal damage)
Does dapsone fix the enteropathy
No, just the dermatitis herpetiformis. People still need to be on gluten free diet to avoid MALT lymphoma formation
Diagnosis of DH
- Subepidermal cleft with neutrophils and few eos at tips of dermal papillae
- IgA on DIF in granular deposits on tips of dermal papillae and along BMZ (not altered if pt on dapsone but gone if gluten free)
- anti-endomysial IgA or anti-transglutaminase IgA testing on serum
- also screen with CBC, TSH, and blood glucose
Diagnosis of linear IgA
just have the IgA at BMZ not dermal papillae tips
Treatment of DH
Dapsone and sulfapyradine/sulfasalazine (2nd line)
- reported treatment with tetracycline and nicotinamide combined
Monitoring while on Dapsone
- first check G6PD level
- then weekly CBC x 1 mo, monthly x 6mo, then two times per year
Adverse reactions to Dapsone
Agranulocytosis, aplastic anemia, peripheral motor neuropathy (resolves over months to years once discontinued)
Dapsone hypersensitivity syndrome
- occurs 1 mo or more after starting, Mono like illness + exanthematous rash +/- hepatitis and hypothyroidism
- treat with atleast 1 mo of prednisone while monitoring organ dysfunction via labs
