Scoring systems in pemphigus.

Pemphigus is a dreaded disease encountered not infrequently in dermatology settings. While scoring systems in various dermatological conditions exist, objective parameters for assessing disease activity and therapeutic responses in pemphigus are not uniform and foolproof. This article presents various scoring systems in pemphigus.

Introduction

Pemphigus, an autoimmune vesicobullous disease characterized by autoantibodies against distinct adhesion molecules of the epidermis, was almost fatal before the advent of corticosteroids in its management.[1] Due to the wide variations in the presentation of the disease, various emerging therapeutic options offered for its treatment and the wide range in responsiveness, this spectrum of diseases has largely been described by various workers in various subjective terms. There was a felt need to devise objective parameters to evaluate the progress of the disease or its response to therapy in order to compare the outcome parameters reported in different studies on a common platform removing all possible inter-observer variability; in short, to lend some method to the madness. An ongoing Cochrane review of clinical trials studying pemphigus revealed an astounding total of 116 outcome measures described in 96 articles over the past 25 years.[2]

The aim of this article is to present on a single platter some salient scoring systems devised on pemphigus.

Scoring Systems

While measurement of body surface area (BSA) involvement using Wallace's rule of nine could, at first glance, provide a simple parameter to assess and grade the severity of pemphigus, it may be too simplistic and is fraught with flaws of subjectivity. Skin area assessments to measure inflammatory skin disease can be difficult, reportedly even for physicians.[3-5]

Pemphigus Area and Activity Score [Table 1] is one of the earliest scoring systems devised for pemphigus. While it caters for BSA and number of lesions, severity description is subjective and quantification of lesions does not incorporate size, making it an imprecise tool for assessing disease activity.[6]

Table 1

Pemphigus area and activity score[6]

Pemphigus Activity Score [Table 2] introduces intensity of steroid and immunosuppressive therapy along with the extent of disease. But it suffers from a lack of differential clinical involvement of mucosal and cutaneous lesions and an insensitive quantification of lesions.[7]

Table 2

Pemphigus activity score[7]

Pemphigus Disease Area Index [Table 3] integrates cutaneous with mucosal disease in well-defined anatomical locations, assesses number and sizes of lesions and also scores post-inflammatory hyperpigmentation of resolving lesions.[8]

Table 3

Pemphigus disease activity index[8]

Autoimmune Bullous Skin Disorder Intensity Score [Table 4] is a quality- and quantity-based score for cutaneous and oral mucosal lesions. This system claims to monitor the clinical status of individual patients over time vis-à-vis inter-patient differentiation assessed by other systems. In addition, this system can be used for assessing autoimmune diseases other than pemphigus alone, and thus is more versatile.[9]

Table 4

Autoimmune bullous skin disorder intensity score[9]

As mucosal lesions in pemphigus often predate cutaneous lesions, are more recalcitrant and recurrent, associated with severe morbidity (halitosis, dysphagia), often improve with reducing depth and not necessarily by reducing count or size, defy BSA assessment and behave differently from cutaneous lesions, an independent scoring system was devised for oral pemphigus [Table 5]. The system is based on a modification of the objectively validated dysphagia grading system by Dakkak and Bennett. It is reportedly useful for other diseases, viz., benign mucosal pemphigoid, herpetic gingivostomatitis and Stevens Johnson syndrome, and eliminates subjective inter-observer variability.[10] The versatility of this system is revealed by the fact that ABSIS system has also borrowed from this scoring system.

Table 5

Saraswat's oral pemphigus scoring[10]

Numerous other scoring systems [Tables 6–9] have also been described in literature at different times to score disease activity of pemphigus.[11-14] International Pemphigus Committee recently came out with a consensus statement on definitions of disease, end points, and therapeutic response for pemphigus which, for the first time, defines common terms and end points of the disease in order to accurately measure and assess disease extent, activity, severity, and therapeutic response at agreed-on time points.[8]

Table 6

Pemphigus vulgaris lesion severity ccore[11]

Table 9

Harman's pemphigus grading[14]

Thusfar, the overwhelming fact revealed is the singular lack of uniformity in comparing disease activity and therapeutic responses. Validating scoring systems and pitting them against each other could be used as a means to compare relative efficacies of various systems. One such study recently compared PDAI with ABSIS and found a better intra-class correlation coefficient for PDAI in reliability of assessing skin activity and in intra-rater test-retest reliability for consistency and reproducibility of scoring, when compared with ABSIS. The study concluded that PDAI was a reliable, quick, and easy-to-use method to capture the extent of skin and mucosal lesions in mild-to-moderate pemphigus, as compared to ABSIS.[15]

Conclusion

Pemphigus, as a group of diseases, is constantly evolving with advances in molecular biology and expanding therapeutic options. While in the past, introduction of steroids remarkably reduced the mortality rate of this dreaded disease, modern times paradoxically incriminate immunosuppressive therapies as one of the major causes of morbidity and mortality in this condition. Hence, the need of an ideal scoring system to assess this disease against contemporary parameters cannot be overstated. Despite a wide array of scoring systems given by various workers, the search for the “perfect one” is still on.

Table 7

Kumar's scoring system[12]

Table 8

Mahajan's scoring system[13]