Indian Journal of Dermatology
CORRESPONDENCE
Year
: 2022  |  Volume : 67  |  Issue : 4  |  Page : 451--454

Epidermolysis bullosa acquisita: A report of four cases


Abhishek De1, Subhra Dhar2, Raghavendra Rao1, Aarti Sarda3, Sandipan Dhar4,  
1 From the Department of Dermatology, Calcutta National Medical College, Kolkata, West Bengal, India
2 Department of Pathology, Wizderm Specialty Skin and Hair Clinic, Kolkata, West Bengal, India
3 Department of Dermatology, Wizderm Specialty Skin and Hair Clinic, Kolkata, West Bengal, India
4 Department of Dermatology, Institute of Child Health, Kolkata, West Bengal, India

Correspondence Address:
Sandipan Dhar
Department of Dermatology, Institute of Child Health, Kolkata, West Bengal
India




How to cite this article:
De A, Dhar S, Rao R, Sarda A, Dhar S. Epidermolysis bullosa acquisita: A report of four cases.Indian J Dermatol 2022;67:451-454


How to cite this URL:
De A, Dhar S, Rao R, Sarda A, Dhar S. Epidermolysis bullosa acquisita: A report of four cases. Indian J Dermatol [serial online] 2022 [cited 2023 Feb 8 ];67:451-454
Available from: https://www.e-ijd.org/text.asp?2022/67/4/451/360306


Full Text



Sir,

Clinically and histopathologically Bullous pemphigoid (BP) often is difficult to differentiate from epidermolysis bullosa acquisita (EBA). Direct immunofluorescence (DIF) which is often considered as the gold standard in the diagnosis of subepidermal bullous diseases, also fails to differentiate between the entities as it demonstrates linear deposition of immunoreactants (most commonly IgG and C3) in the BMZ in both conditions.[1]

These features have resulted in the misdiagnosis of EBA as BP, especially in a resource-poor setting, making EBA a vastly underappreciated entity in such situations. Salt split technique (SST), using 1 mol/L NaCl offers a simple yet under-utilized tool to differentiate EBA from BP.

We report here four cases of EBA, which presented to a tertiary center of eastern India in six years (2014-2020), to emphasize the utility of the SST in the routine diagnostic algorithm of SIBD.

Out of the four patients, three were female and one was male. The average of the presentation was 41.8 ± 15.6 years (Range = 26 years to 60 years). The mean duration of disease at presentation was 17.8 ± 12.5 months. The most common site of involvement was the upper limbs, followed by the lower limbs and trunk. Blisters were mostly on the extensor-sides of limbs and trunk, and in two cases, blisters were more common in the pressure prone areas. Blisters healed with mild to moderate scarring [Figure 1], [Figure 2], [Figure 3], [Figure 4].{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Two of our cases had associated diabetes and one had hypertension. None of the cases showed any mucosal involvement.

Clinically three cases were provisionally diagnosed as BP, and one had a differential diagnosis of BP/EBA: in our autoimmune bullous disease clinic.

Excision biopsy from small intact blisters were sent for histopathology and showed subepidermal cleft with sparse infiltrate in the dermis, predominantly polymorphonuclear in nature with concomitant presence of lymphocytes. All four cases were provisionally diagnosed as BP by the pathologist [Figure 5] and [Figure 6].{Figure 5}{Figure 6}

We performed a 3 mm skin punch biopsy from the uninvolved perilesional skin for DIF studies. Routine DIF detected a linear band of IgG and/or C3 at Basement Membrane Zone (BMZ) in all four cases. One case had an additional immunoreaction of faint linear IgA at BMZ. The diagnosis of all four cases after routine DIF was equivocal, as SIBD, as routine DIF failed to differentiate between BP and EBA.

We performed the SST as described by De et al.,[1] in all these four cases. In SSS, all these four cases took a floor pattern (faint roof stain was seen additionally in a single case). By performing the SST, we were able to reach a final diagnosis of EBA in all four cases, emphasizing the value of this simple technique in the routine diagnostics of SIBD [Figure 7] and [Figure 8].{Figure 7}{Figure 8}

EBA is an immunologically distinctive disease from other SEBD. Classically, EBA has characteristic clinical features. These include extreme skin fragility, trauma-induced blisters and erosions, and healing with scars and milia. Sometimes, inflammatory form of EBA masquerades as BP, and studies suggested that BP-like clinical presentation occurs in as many as 50% of EBA patients, and at least 10% of patients referred to medical centers and diagnosed as BP have EBA. These patients will have tense blisters on erythematous or urticarial background which heals without scarring or milia formation [Table 1].[2]{Table 1}

It is imperative for the clinician to make every effort to distinguish BP from EBA for three reasons: 1. EBA has been known to be associated with various systemic diseases such as inflammatory bowel disease (IBD) 2. BP can often be associated with malignancy especially in the elderly, 3. EBA is relatively resistant to treatment.[3]

SST using 1 M NaCl is a simple tool that aids in the differentiation of BP from EBA. In BP, where autoantibodies target BP antigen 1 & 2 of basal keratinocytes or anchoring filaments, the immuno-reactants have either a roof pattern or a mixed pattern in a skin split at lamina lucida with the help of 1 M NaCl. In contrast, EBA has autoantibodies targeting anchoring fibrils of sub-lamina densa, therefore the immuno-reactants take the floor pattern [Table 1].[4]

We present here these four cases to highlight that direct SST is a simple, cheap, and easy tool and should be routinely employed in immunofluorescence studies of patients with SEBD. In resource-poor settings where advanced diagnostics like immunoblotting, immunoelectron microscopy, or indirect IF using toad skin are not available, this simple yet effective technique can give us important diagnostic clues while dealing with SEBD.

Our limitation was that we could not differentiate EBA from anti-p 200 pemphigoid, which is a rare SIBD initially described in 1996. These two entities could have been differentiated by performing indirect immunofluorescence, in collagen VII depleted recessive dystrophic epidermolysis bullosa skin.[5]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1De A, Rao A, Balachandran C. Salt split technique: A useful tool in the diagnosis of subepidermal bullous disorders. Indian J Dermatol 2010;55:334-6.
2Woodley DT. Immunofluorescence on salt-split skin for the diagnosis of epidermolysis bullosa acquisita. Arch Dermatol 1990;126:229-31.
3Reddy H, Shipman AR, Wojnarowska F. Epidermolysis bullosa acquisita and inflammatory bowel disease: A review of the literature. Clin Exp Dermatol 2013;38:225-9; quiz 229-30.
4Satyapal S, Amladi S, Jerajani HR. Evaluation of salt split technique of immunofluorescence in bullous pemphigoid. Indian J Dermatol Venereol Leprol 2002;68:330-3.
5Kridin K, Ahmed AR. Anti-p200 Pemphigoid: A systematic review. Front Immunol 2019;10:2466. doi: 10.3389/fimmu. 2019.02466.