title: Lichen Planus Pemphigoides Presenting Preferentially Over Preexisting Scars: A Rare Instance of Isotopic Phenomenon.
abstract: An 18-year-old girl presented with multiple itchy hyperpigmented papules and plaques, along with tense blisters over the lower limbs and buttocks for last 3 months. These papules, plaques, and bullae were mostly localized to preexisting scars. The histopathological findings from papule and bulla were consistent with lichen planus (LP) and bullous pemphigoid, respectively. Direct immunofluorescence (DIF) of perilesional skin around bulla showed linear deposition of IgG and C3. Considering clinical, histopathological and DIF findings, diagnosis of LP pemphigoides (LPP) was made. The preferential localization of LPP lesions over preexisting scars was a very interesting finding in our case an extremely rare instance of the isotopic phenomenon.
authors.affiliation: Department of Dermatology, Katihar Medical College, Katihar, Bihar, India.
authors.forename: Piyush
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Dermatology, Katihar Medical College, Katihar, Bihar, India.
authors.forename: Sushil S
authors.initials: SS
authors.lastname: Savant
authors.affiliation: Department of Dermatology, Medical College and Hospital, Kolkata, Kolkata, West Bengal, India.
authors.forename: Anupam
authors.initials: A
authors.lastname: Das
authors.affiliation: Department of Dermatology, Katihar Medical College, Katihar, Bihar, India.
authors.forename: Shahid
authors.initials: S
authors.lastname: Hassan
authors.affiliation: Mahatma Gandhi Missionary New Bombay Hospital and Research Center, Vashi, Navi Mumbai, Maharashtra, India.
authors.forename: Panchami Deb
authors.initials: PD
authors.lastname: Barman
keywords: Bullous lichen planus; Wolf's isotopic response; lichen planus pemphigoides