Chronic Bullous Dermatosis of childhood is the most common, non- hereditary autoimmune blistering disorder of childhood. It is characterized by the presence of continuous linear deposits of IgA autoantibodies along the basement membrane zone [1]. In this case report, the key features of this rare Autoimmune Bullous Disease are revisited.

Diagnosis of Chronic bullous dermatosis requires 3 criteria, that is a vesicular or a bullous eruption involving the skin or mucous membrane, A subepidermal neutrophilic predominate infiltration on histology and basement membrane deposition of IgA on a linear manner [2].

The antigens involved in this are LAD-1 and LABD97, which represent the extracellular collagen of XV11 [3].The pathogenesis involves both cell and humoral mediated immunity, production of IgA antibodies against the antigens and the linear pattern of deposition determines the humoral response [4]. The cellular response is by complement activation and by the release of proteolytic enzymes [5].

CBDC commonly affects the preschool group of children, although a few cases of neonatal CBDC has been reported [1,3].

It usually presents as tense polymorphic blisters, with the newer lesions forming annular rings around the older lesions with peripheral blisters known as the “string of pearls” sign [6]. These lesions are usually pruritic or non-pruritic arising from normal or erythematous skin base [1]. Predominant location includes the lower extremities and genital region with occasional involvement over the face and upper extremities [3].

Differential diagnosis includes bullous impetigo, dermatitis herpetiformis, bullous pemphigoid, erythema multiforme [1]. Lesional skin histology reveals a neutrophilic predominant subepidermal cavity [3]. Direct immunofluorescence shows linear IgA deposition, literature has also shown deposition of IgG, IgM, C3 [7,8].

Commonly used therapy includes dapsone and sulfapyridine, which helps to achieve long-lasting remission [9].Dapsone combined with steroids that can be used as monotherapy in generalized CBDC [10]. Other immunosuppressive agents used are cyclosporine, methotrexate, and cyclophosphamide [2].

Fig-4: Completely resolved lesions over the forearm.

The largest among them was seen on the palms. Serosanguinous foul-smelling discharge was associated with the lesion. There was pronounced itching. A characteristic string of pearl appearance was not seen, only isolated lesions were noted. Tense bullae with the erythematous base were present asymmetrically. On examination, the Nikolsky sign was absent. The mucous membrane, hair, and nails were spared.

There was no family history of the cutaneous disease and a history of any drug intake or any history of upper respiratory tract infection. No history of trauma, exposure at the site of blisters.

Investigations revealed normal counts with poly predominance with mild eosinophilia. The erythrocyte segmentation rate was elevated. The coagulation profile and the International normalized ratio were within normal limits. CRP was elevated (2.4). Direct smear – gram stain from the left leg showed an abscess with occasional pus cells, occasional epithelial cells, and no organisms. Pus culture and blood culture were sterile.

Histopathological examination revealed linear fragments of tissue shown of parakeratosis with overlying hyperkeratosis. It also revealed many eosinophils are scattered with few micro abscesses within the parakeratotic column. Thus, the roof of the bulla showed increased eosinophils in the parakeratotic layer.

The child was initially started with IV antibiotics with the suspicion of infected bullae. The child had received IV cloxacillin and IV vancomycin for 3 days. The child received IV hydrocortisone (1mg/kg/dose) with IV acyclovir. Derooting of the bullae was done with biopsy and silver arginate dressing was applied. The lesions were was refractory.