Localized Bullae

This healthy 83 year-old man has had a one year history of bullae and vesicles on the medial aspect of the left knee. They come and go. He is on no new medications and does not take any drugss on an as necessary or intermittent basis. His medications consist of valsartan (Diovan), simvastatin and omeprazole (Prilosec).

O/E: A collection of vesicles and bullae left knee.

Clinical Photo:


Lab and Path:
Bacterial Culture 8/14/o9 Negative
Biopsies were done by two other dermatologists (will try to get results). Apparently, no firm diagnosis was made.

Path Report: 9/30/08 Perivascular and interstitial dermatitis with mixed cell infiltrate including eosiniphils. Dermal hypersensitivity reaction. "These findings may be seen in the prebullous lesions of pemphigoid." DIF was negative.

Diagnosis:
Consider localized bullous pemphigoid.

Discussion: This is an 82 yo man with a one year history of a localized bullous disorder. The initial pathology showed an inflammatory process with eosinophils. The bullous process has stayed localized to the left knee. It seems likely that this is localized bullous pemphigoid. There is a "pretibial variant" and this may be related. Apparently, many of these patients have negative direct immunofluorescence (See ref. below)
Plan to treat initially with clobetasol ointment and if does well follow with tactolimus ointment 0.1%.

Questions: What do you think? What else is in your differential diagnosis? Therapeutic options?

Reference:

Kurzhals G, et. al. [Localized cicatricial bullous
pemphigoid of the Brunsting-Perry type] Hautartz.
1993 Feb;44(2):110-3 [Article in German]
Localized cicatricial pemphigoid of the Brunsting-
Perry type is a very rare bullous condition, which
has so far been reported in 51 cases. It is
characterized by scarring blisters confined to the
head, scalp and neck.  Diagnosis can be difficult
because of the discrete skin lesions, often repeatedly
false-negative direct immunofluorescence, and the
absence of circulating antibodies. We report on a
87-year-old male patient with the typical clinical
feature of a cicatricial pemphigoid of the Brunsting-
Perry type and give a reviewof the 51 cases published
in the world literature.

Follow-up Photo (08/21/09):  The patient was seen after a week for a second visit.  No
treatment had been rendered and the bullae had resolved.  One wonders
what triggers the bullae?  He's a tennis player, so could it be minor
trauma, UVL?