Case Number : Case 1415- 25 November Posted By: Guest

The images correspond to a cell poor subepidermal blíster with areas of spongiosis. Immunofluorescence is of course primary and the differential is wide but would have to think about epidermolysis bullosa, bullous LE (that can be cell poor), etc. Still the clinical setting in this case as well as vertical elongation of keratinocytes makes me consider also bullae developing after physical trauma like cryotherapy or burns

Difficult case. I see a subepidermal blister with scattered inflammatory cells and my ddx is mostly EB and Porphyria cutenea with the eosinophilic bodies seen representing "caterpillar" bodies. DIF is necessary.

Agree with all above suggestions, also will add diabetic bullae

Will add more clinical information: 4 day history of acute onset of blisters, not on any medications, otherwise fit and well. Not diabetic. Porphyrin screen negative. Direct IMF negative.
Hope that narrows the differential...

Bullous insect bite reaction!

I dont favor bullous insect bite because in the clinical description is written legs (bilateral). I still think it could be a physical damage of skin like cryotherapy, burns, suction, etc (even if usually the epidermis is necrotic in these cases). There is also bullous amyloidosis which I dont favor. Any history of physical injury or therapy Arti?

I once saw a case like this with necrotic keratinocytes caused by Munchausen syndrome. Another ddx.

This is a case of Bullous Dermatitis Artefacta, most likely due to thermal/cryo injury. Many of you were on the right track, so well done for that! Extra kudos to Raul for nailing the diagnosis even before the full clinical history and rightly observing the characteristic 'vertical elongation of keratinocytes' that I was trying to show in images 3 and 4. There is also superficial epidermal necrosis with loss of cytoplasmic detail in superficial keratinocytes. These features are indicative of thermal/cryo injury. (see reference below which describes remarkable similar histology in 2 patients with bullous DA). The patient had not had any medical procedure and the patient denied any trauma. When I discussed the case with the dermatologist, she felt the clinical presentation (large bizarre shaped blisters, acute onset, patient demeanour etc) were consistent with DA. Ofcourse, other differentials incl porphyria, pseudoporphyria and autoimmune bullous disorders needed to be excluded, which was done by appropriate tests.
[url="http://www.ncbi.nlm.nih.gov/pubmed/22771895"]http://www.ncbi.nlm.nih.gov/pubmed/22771895[/url]

Shame I did not have a go yesterday. The age and rather abrupt necrosis of the epidermis (upper left image), and lack of any bone fide pathology underneath shouts external factors. Good that the clinical colleagues were thinking likewise.