Bullous Pemphigoid Diagnosis and Treatment

Clinical Features and Diagnosis

The British Journal of Dermatology recommends that a diagnosis of bullous pemphigoid (BP) be considered in patients with tense bullae arising on erythematous or normal-appearing skin, most commonly on flexural surfaces of limbs, inner thighs, and trunk 1, 2
The presence of pruritus preceding blister formation by weeks to months is a key diagnostic criterion, as reported by the British Journal of Dermatology 1, 2
The absence of atrophic scarring after healing and minimal or absent mucosal involvement are also characteristic features of BP, according to the British Journal of Dermatology 1, 2
Direct immunofluorescence (DIF) from perilesional skin is the single most critical and essential test for diagnosis, showing linear IgG and/or C3 deposits along the dermoepidermal junction, as recommended by the British Journal of Dermatology 2
Histopathology from an early intact bulla showing subepidermal cleft with eosinophilic infiltrate is an additional confirmatory test, as reported by the British Journal of Dermatology 2
Serum ELISA for anti-BP180 and anti-BP230 antibodies is also a useful diagnostic tool, although DIF remains the most critical test, according to the British Journal of Dermatology 2

The British Journal of Dermatology recommends superpotent topical corticosteroids as the first-line treatment for localized/mild disease (<10% body surface area) 1, 3
For moderate to severe/generalized disease, systemic corticosteroids remain the cornerstone of treatment, with an initial dose of prednisolone 0.5 mg/kg/day orally, as recommended by the British Journal of Dermatology 1, 3
The aim of treatment is to suppress clinical signs sufficiently to make disease tolerable, not necessarily achieve complete remission, as reported by the British Journal of Dermatology 1
BP is self-limiting and usually remits within 5 years, with mortality rates ranging from 6-41% in modern series, primarily due to complications of immunosuppression in elderly patients with multiple comorbidities, according to the British Journal of Dermatology 1, 3
The British Journal of Dermatology recommends evaluating general condition and comorbidities using the Karnofsky performance status scale, and monitoring for corticosteroid adverse effects and disease activity using validated tools such as the Bullous Pemphigoid Disease Activity Index 2, 3
Linear IgA disease can be distinguished from BP by the presence of only IgA (not IgG) on DIF, as reported by the British Journal of Dermatology 1

The British Journal of Dermatology recommends that a diagnosis of bullous pemphigoid (BP) should be considered in patients over 70 years old presenting with tense bullae on the hand and a negative Nikolsky sign 4, 5, 6
Age >70 years is a key diagnostic criterion for BP, as it typically affects elderly patients with a mean age of onset around 80 years 4, 5
Tense bullae are the hallmark of BP, arising on erythematous or normal-appearing skin, most commonly on the limbs and trunk 4, 5, 6
A negative Nikolsky sign is characteristic of BP and helps distinguish it from pemphigus vulgaris and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) 5, 6

In SJS/TEN, the Nikolsky sign is positive, with flaccid bullae, extensive mucosal involvement, and constitutional symptoms including fever and malaise 7, 8
In pemphigus vulgaris, the Nikolsky sign is positive, with flaccid (not tense) bullae and prominent mucosal involvement 9
In staphylococcal scalded skin syndrome (SSSS), the Nikolsky sign is positive but mucosal involvement is absent, which helps distinguish it from TEN 7, 9

Direct immunofluorescence (DIF) from perilesional skin showing linear IgG and/or C3 deposits along the dermoepidermal junction is the gold standard and essential for diagnosis 5, 6, 10
Histopathology from an early intact bulla showing subepidermal clefting with eosinophilic infiltrate is also a key diagnostic test 4, 5, 6
Serum ELISA for anti-BP180 and anti-BP230 antibodies can be used, though DIF remains the most critical diagnostic test 4, 5, 10

High specificity (95%) for BP when three of four criteria are present with positive DIF: age >70 years, absence of atrophic scarring, absence of mucosal involvement (or minimal involvement), and absence of predominant bullous lesions on neck and head 5, 6, 11