Itchy papula vesicular lesions on extremities MCQ | Medical PG Preparations

30 year old male had severely itchy papula vesicular lesions on extremities, knees, elbows and buttocks for one year. Direct immunofluorescence staining of the lesions showed IgA deposition at dermoepidermal junction. The most probable diagnosis is

A Pemphigus vulgaris 

B. Bullous pemphigoid

C. Dermatitis herpetiformis 

D. Nummular eczema

Ans. C. Dermatitis herpetiformis. 

Dermatitis herpetiformis - manifested by pruritic papules, vesicles, and papulovesicles mainly on the elbows, knees buttocks, posterior neck, and scalp

Associated with HLA-B8 -DR 3 and DQ-2

Diagnosis

1. Neutrophils at the dermal papillary tips

2. Granular deposition of IgA along the dermal papillae

3. Circulating anti endomysium antibodies and antibodies to tissue transglutaminase are present in 70% cases

Pemphigus vulgaris- Deposition of IgG and C3 on the surface of keratinocytes against desmoglein.  intercellular

Bullous pemphigoid - Linear band of IgG and/or C3 in epidermal basement cone.

Patients have gluten sensitive enteropathy

Patients with dermatitis herpetiformis are at increased risk of development of GI-lymphoma

Treatment - Gluten free diet, Dapsone*

DIRECT IMMUNOFLUORESCENCE FINDINGS IN AUTOIMMUNE BLISTERING DISEASE.
Disease	Pattern and nature of immunoreactants
Pemphigus	Epidermal cell-surface deposits of IgG and C3
Bullous pemphigoid	Linear, homogeneous deposits of IgG epidermal side on salt-split skin.  and C3 at the dermal-epidermal junction.
Linear IgA dermatosis	Linear homozeneousdepositsof IgA at the dermal-epidermal iunction
Herpes gestationis	Linear homogeneous.depositsof C3 at the dermal-epidermal junction
Epidermolysis bullosaacquisita	Linear homogeneous deposits of IgG dermal side on salt-split skin.  and C3 at the dermal- epidermal iunction.
Cicatricial pemphigoid	Linear homogeneous deposits of IgG and C3 at the dermal-epidermal junction
Dermatitis herpetiformis	Focal granular deposits of IgA at the papillary tips
Bullous eruption of lupus erythematosus	Linear homogeneous, or non-homogeneous, deposits of multiple immunoglobulins, C3 and fibrin at the dermal-epidermal junction.