This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immune system, Subject name: Medicine
A Young boy presents with multiple flaccid bullous lesions over trunk with some oral mucosal lesions. Most likely finding on immunofluorescence study of the biopsy specimen would be 
Select and explain. 
A. 'Fishnet' IgG deposits in epidermis, B. Linear IgG in Deposits, C. Linear IgA in dermal papillae, D. Granular IgA in reticular dermis
A: 'Fishnet' IgG deposits in epidermis
Answer: A: 'Fishnet' IgG deposits in epidermis 
Explanation: Pemphigus Vulgaris Bullous pemphigoid Autoantibodies against Desmosomal proteins Hemidesmosomal proteins Age 40-60 yrs 60-75 yrs Initial site Oral mucosa Lower extremities Bullae Flaccid Tense Pruritus Mild/- Nonexistent or severe Nikolsky's sign + - Mucosal involvement +(in almost all patients) - (10-40% only) HPE Suprabasal acantholytic blisters (Tombstone appearance) Q Subepidermal blisters (eosinophil-rich dermal infiltrate) DIF IgG & C3 deposits at the intercellular substance of epidermis ("Fishnet appearance")Q IgG, C3, and IgA/IgM at BM zone. IIF Circulating IgG antibodies to the intercellular substance of epidermis. Anti-BM zone antibodies IgG Rx Steroids + immunosuppressants Dapsone Gold Steroids Immunosuppressants Dapsone Postinflammatory Hyperpigmentation + - (Ref. Harrison's 19th ed. Table 55-1)