|Year : 2013 | Volume
| Issue : 1 | Page : 80-81
Linear IgA bullous dermatosis
Nandakishore Thokchom, Dilimpou Pamei
Department of Dermatology, Venereology and Leprology, RIMS, Imphal, Manipur, India
|Date of Web Publication||17-Aug-2013|
Department of Dermatology, Venereology and Leprology, RIMS, Imphal, Manipur
Source of Support: None, Conflict of Interest: None
Linear IgA disease is a rare chronic autoimmune subepidermal blistering disorder characterized by the linear deposition of IgA along the dermoepidermal junction. A 40-year-old housewife presented with symmetrically distributed generalized intensely pruritic vesiculobullous lesions of 1 year duration. Previous treatment with oral and topical steroids had induced only a temporary remission of the skin lesions. There was no history of drug intake in the recent past and her medical history was insignificant and there was no similar illness in her family members. Examination findings included vesicles arranged at the periphery of healed lesions along with post-inflammatory hyperpigmented macules on the trunk and extremities. There was no genital, mucosal or ocular involvement. Skin biopsy from the leg showed dense neutrophilic infiltration along with eosinophils at the tip of the dermal papillae and focal areas showed dermoepidermal clefting with bulla formation. Direct immunofluorescence of perilesional skin revealed linear deposits of IgA at the basement membrane zone. Therapeutically the patient responded well to dapsone. Though the presentation was classical, the case is reported for its rarity.
Keywords: Bullous disease, Direct immunofluorescence, Linear IgA
|How to cite this article:|
Thokchom N, Pamei D. Linear IgA bullous dermatosis. J Med Soc 2013;27:80-1
| Introduction|| |
Linear IgA bullous dermatosis (LABD) is a rare autoimmune blistering disease characterized by subepidermal blisters and linear deposition of IgA autoantibodies at the dermo-epidermal junction. 
The clinical manifestations of LABD are heterogeneous and may mimic other uncommon blistering skin diseases especially erythema multiforme, bullous pemphigoid, and dermatitis herpetiformis. Thus, it is difficult for clinicians to make the diagnosis of LABD with confidence. The only way to distinguish LABD from other subepidermal blistering disorders is by direct immunofluorescence (DIF) testing that shows a linear IgA band at the dermo-epidermal junction.  We are reporting a case of LABD who responded well to dapsone.
| Case Report|| |
A 40-year-old housewife presented with a 1-year history of symmetrical generalized intensely pruritic vesiculobullous skin eruptions on the trunk and extremities. There was no mucosal, genital or ocular involvement. There was no personal or family history of skin diseases and medical history was unremarkable.
Physical examination revealed generalized vesiculobullous lesions with vesicles arranged at the periphery of healed lesions [Figure 1] along with post inflammatory hyperpigmented macules distributed on the trunk and extremities.
|Figure 1: Vesicles arranged at the periphery of healed lesions with post inflammatory hyperpigmented macules|
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Bullae were tense and Nikolsky sign was negative. Crusted and excoriated lesions were also present. Scalp also revealed crusted lesions. Face, palms, and soles were spared.
Histological examination of the skin biopsy showed dense neutrophilic infiltration in the tip of the dermal papillae and focal areas showed dermoepidermal clefting with bulla formation [Figure 2]. Direct immunofluorescence studies detected linear deposits of IgA in the basement membrane zone (BMZ) [Figure 3]. Routine investigations were normal. The clinical, histologic and the immunopathologic findings were consistent with a diagnosis of LABD of adults. The patient was treated with dapsone 100 mg daily and the patient had been in remission on the last follow-up at 6 months.
|Figure 2: Dermo-epidermal clefting with dense neutrophilic infiltration in the dermal papillae with eosinophils|
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|Figure 3: Direct immunoflourescence showing linear deposits of IgA in the dermo-epidermal junction|
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| Discussion|| |
LABD is due to IgA auto-antibodies typically directed against the soluble shed ectodomain of BP180Â antigen known as linear IgA disease antigen, a 97Â or 120 kD protein, and/or other components of dermal-epidermal junction. 
Circulating IgA anti-BMZ antibodies are found in 60-70% of the cases. The true incidence is unknown. The incidence in southern England has been estimated to be 1/250,000/year. 
The disease may be either idiopathic or triggered by several medications, most often with vancomycin.  LABD has also been rarely associated with lymphoma, hematological conditions, rheumatological conditions, ulcerative colitis, and solid tumors. 
There is no specific clinical marker for LABD. In adults, eruption is polymorphic and very atypical presentations have been described. Only mucosal involvement without skin lesions have also been reported causing diagnostic confusion. 
Diagnosis is confirmed by DIF which shows linear IgA deposition on the BMZ. Based on the localization of IgA deposits, LABD is classified into lamina lucida type and sublamina densa type on immunoelectronmicroscopic study. 
The first-line of treatment for LABD is dapsone either as monotherapy or combined with systemic corticosteroids. Other medications that have been reported to help individual patients include: Sulfonamides (sulfapyridine), antibiotics (tetracycline, erythromycin, dicloxacillin), corticosteroids and steroid-sparing agents (mycophenolate mofetil, azathioprine, IV Ig, cyclosporine). 
Only very few cases has been reported from India. It was first reported by Ajithkumar et al.  in 1997 wherein the authors described five cases of adult LABD from South India. To the best of our knowledge, this is the first report from North-East India. Though classical, we report this case for its rarity and to emphasize that DIF is mandatory for proper diagnosis and treatment of bullous diseases of the skin.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]