Generalised recessive dystrophic epidermolysis bullosa in two sisters

Introduction

Epidermolysis Bullosa (EB) comprises a group of genetically determined disorders characterised by blistering of skin and mucosa following mechanical trauma and sometimes developing spontaneously.[1] They are also termed mechanobullous disorders. At least 19 subtypes of EB are known to exist. They have varied prognosis depending on the extent of cutaneous involvement and pattern of inheritance. Hence the importance of specific diagnosis. A rare subclass of EB with poor prognosis was encountered in two female siblings of a family. The case is reported to heighten clinical awareness of this condition.

Case Report

Two sisters 9 years and 5 years of age respectively, born of a non consanguinous marriage presented with history of fluid filled lesions over trunk and limbs since birth erupting spontaneously as well as after trauma, that healed with scars. There was history of summer exacerbation, photoaggravation, and Koebnerisation. Both had developed oral ulcers causing dysphagia and corneal ulcers off and on. A 3 year-old-male sibling was asvmotomatic and normal. There was no history of atopy.

General Examination: Older girl : 5th percentile (height 112 cm and weight 15 Kg) and younger girl: 5th percentile (height 92cm and weight 9 Kg). Systemic examination of abdomen, CVS, CNS and chest was normal. DermatologicaI examination ravealed a few flaccid bullae, extensive erosions and atrophic scars over face, trunk, both upper limbs and both lower limbs with predominance over the bony prominences of the elbows, knees, dorsa of both hands and feet. Nikolsky′s sign was positive. One girl had pseudowebbing of the middle finger of the left hand. [Figure - 1]. Fingernails and toenails were absent. Milia, oral ulcers and discrete cicatricial alopecia of the scalp were present. Teeth were malformed and carious. Both eyes had sclerokeratitis with haziness at sclerocorneal margin. Palms, soles and genitalia were normal. Routine investigations were normal. Urine for porphyrins was negative. Skin biopsy revealed sub epidermal bullae. Based on the clinical and histopathological evidence, they were diagnosed as Generalised Recessive Dystrophic Epidermolysis Bullosa (RDEB) or Hallopeau-Siemens syndome. Both were treated with topical and systemic antibacterials when indicated. They were given oral phenytoin for months, but the condition remained unchanged on follow up.

Discussion

EB is broadly classified into simple, junctional and dystrophic types when the histological level of cleavage and blister formation is above, within or below the dermo-epidermal junction respectively. Simple and non lethal forms of junctional types are clinically mild, non scarring, have a better prognosis and generally improve with age. The dystrophic forms of EB are characterised by scarring, nail changes and milia.[1] A lack of immunofluorescence reaction with monoclonal antibodies to anchoring fibrils and with polyclonal antibodies to type VII collagen (a component of anchoring fibrils) establishes abnormalities of anchoring fibrils in generalised RDEB.[2],[3] Another pathogenic abnormality reported in RDEB is an increased level of collagenase in the non blistered skin.[4] As a result, cutaneous integrity is weak, causing skin cleavage with minor trauma, and healing with scars and milia. Retarded physical development, cutaneous scars, mucosal erosions, corneal erosions, deformed teeth, dystrophic nails and cicatricial alopecia are common manifestations of RDEB. The treatment is mainly symptomatic and supportive, and is aimed at preventing cutaneous, mucosal and dental infections. Phenytoin has been suggested as a therapeutic modality, but has reportedly varied responses.[5] In early disease, oral erosions complicate feeding and later may cause recurrent oesophageal ulcers leading to stricture formation and dysphagic pneumonitis. But the most significant late complication is squamous cell carcinoma of chronically scarred skin, oesophagus and mouth.

Our case had all the classical features of generalised RDEB. Early detection precluded any malignancy. But it demands a regular follow-up to manage any malignancies that may arise later.