The correct answer is D. Dermatitis herpetiformis
Correct Answer Explanation
Dermatitis herpetiformis or Duhring’s disease, presents with very pruritic vesicles symmetrically on extensor surfaces. On histology it presents as suprapapillary vesicles with mostly neutrophils and inflammatory destruction of the basement membrane zone. Direct immunoflourescence shows granular deposition of IgA in the dermal papillae and along the basement membrane zone.
Incorrect Answer Explanation
The other listed diseases do not display this patter of fluroescence of DIF.
Barnadas MA. Dermatitis Herpetiformis: A Review of Direct Immunofluorescence Findings. Am J Dermatopathol. 2016 Apr;38(4):283-8. doi: 10.1097/DAD.0000000000000420. https://www.ncbi.nlm.nih.gov/pubmed/26630684