Cutaneous Autoimmune Blistering Disease • ~ Pathology Case Review • ~2004, March/Aprial

Cutaneous blister • Result of significant spongiosis, balloning degeneration, basal vacuolopathy, inherited disorder or autoimmune destruction • Histology, DIF and clinical history to arrive at the correct diagnosis

Case 1 • 24 y/o black woman with tense 2-3 cm fluid-filled blister on the upper extremity, joint pain and swelling • Hx of SLE • progress to involve the forehead and lower extremity • LM: subepidermal blister with a dense neutrophilic infiltrate

Case 1 • DIF: linear Ig G, IgA and IgM deposition along the BM • IIF: deposition along the floor of the skin

Case 1 • Beyond the mechanism of disruption, the levels of separation and the type of inflammatory responses help to further characterize the process • Confirmation of autoantibody deposition: DIF, IIF, immunoblot, immunoprecepitation • Immnoelerctorn microscopy • Salt split skin : subepidermal blistering dx

Porphyria cutanea tarda(PCT) • Sun exposed sites • Paucicellular subepidermal blister • Reduptication of the vascular and epidermal basement membrane • DIF: IgG and C3 trapped in vascular wall

Epidermolysis bullosa acquisita (EBA) • Blister on acral and trauma-prone sites • DIF: IgG and C3 deposition along the floor of separation • Other D/D: urticarial variant of BP, suction blister, blister due to cryotherapy or heat, inherited epidermolysis bullosa variant, TEN

Bullous pemphigoid(BP) • Over 60 y/o, bullae on the trunk and extremity • Subepidermal blister with inflammatory infiltrate( predominant eosinophil) • DIF: linear IgG along the BM • IIF: deposition on the roof

Dermatitis herpetiformis(DH) • Adult with a chronic pruritic eruption • Strong genetic predisposition • DIF: IgA and C3 in the tip of dermal papilla

Linear IgA dermatosis • Childhood and adult type • DIF: not just localized to the dermal papilla but also along the dermal epidermal junction

Cicatrical pemphigoid(CP) • Oral and conjuctival blister in elderly p’t • autoAb: direct against BPAg2 of the hemidesmosome, dpiligrin in the lamina densa and type VII collagen

Bullous systemic lupus erythematosus(BSLE) • An uncommon manifestation of SLE • PMN deeper in the papillary dermis and around vessel • DIF: linear or granular deposition of IgG and complement along the BM • Direct against collagen VII

Case (2) • 38 y/o man with extensive painful erosions of the lip and tongue • Polymopphous lichenoid plaque, LAPs • LM: basal vaculopathy with a suprabasal blister, lymphocyte exocytosis, keratinocyte necrosis, suprabasal acantholysis • DIF: BM, intercellar deposistion IgG

Pemphigus foliaceous(PF) • Subcorneal bilster on the head and neck • Never involve mucosal surface • Ab to desmoglein • DIF: IgG fishnet pattern

Pemphigus erythematosus • Well-circumscribed lesions on the malar area • DIF: IgG,C3 in both BM and intercelluar • 30% positive ANA and associated with other autoimmune disease

Pemphigus vulgaris(PV) • Painful oral ulcer • Blister at the most basal layer of the epidermis, loss of cell-cell adhesion with maintenance of attachment to the BM • DIF: IgG, C3 on the keratinocyte, Ab to desmoglein

Paraneoplastic pemphigus(PNP) • Occurs exclusively in the neoplasm • Complex set of autoAb to one or more proteins that play key roles in cell-cell adhesion • Significant variability in histologic features • IIF:intercelluar staining

Other D/D • Acute spongiosis, viral infection, Hailey Hailey disease, Darier disease, Grover disease, friction blister

Summary • Cutaneous autoimmune bilstering dx have many overlapping clinical and histological features and rely on clinicopathological correlation • The level or separation, the type of inflammatory infiltrate and IF pattern • nonAb mediated mediated process

total BP LE LCV pemphigus PF 3 2 8 4 157 31 Our experience Bullous drug eruption 2 pemphigus vegetans 2 superficial fungal inf dermatomyositis 2 2

• Other: epidermolysis bullosa simplex • EBA • EM • Lichen plans pemphgioids • Bullousis diabeticum • H.P. purpura • Bullous amyloidosis • Granuloma faciala • Pigmented purpura dermatosis