Epidermolysis bullosa pruriginosa: Report Of A Rare Case
A Bansal, V Mahajan, N Sharma, N Sud, A Lath, N Gupta
dystrophic epidermolysis bullosa, epidermolysis bullosa, hereditory dermatoses, mechanobullous disorder
A Bansal, V Mahajan, N Sharma, N Sud, A Lath, N Gupta. Epidermolysis bullosa pruriginosa: Report Of A Rare Case. The Internet Journal of Dermatology. 2007 Volume 6 Number 2.
Epidermolysis bullosa prurugenosa is an extremely rare variant of dystrophic epidermolysis bullosa in which combination of intense pruritus and skin fragility lead to hypertrophic, lichenified nodules and plaques and show scarring, milia and nail dystrophy. Histologically, features of hyperkeratosis, acanthosis and minimal blistering at dermal-epidermal-sublamina level are characteristic. Most cases are inherited as autosomal recessive, dominant or sporadic. Its onset is often late, the clinical course is unpredictable and various factors leading to intense pruritus remain speculative. Diagnosis is from characteristic clinicopathologic features. The defect in anchoring fibrils has been attributed to mutations in
Dystrophic epidermolysis bullosa (EB) comprises a heterogeneous group of inherited mechanobullous disorders characterized by trauma induced blistering, scarring associated with milia formation, and nail dystrophy. Both recessive and dominant forms of dystrophic EB are caused by mutations in the
A 40-year-old male, born to non-consanguineous parents after an uneventful pregnancy and birth, presented with symmetrical, itchy, moist, prurigo-like hypertrophic lesions over extremities and back since childhood. The intense pruritus was socially embarrassing and often disturbing sleep. History revealed that he has been developing small blisters over extremities following minor trauma since childhood. These blisters used to rupture and the erosions would heal with scarring. The severity and frequency of blistering decreased with age but he had developed persistent pruritic nodulo-plaques. Historically his severe pruritus could not be attributed to atopy, food or drug allergy, cutaneous or any systemic disorder. His parents and other siblings were reportedly healthy. Topical or systemic steroids and antihistamines had provided temporary relief in the past.
Cutaneous examination showed numerous excoriated and lichenified papules coalescing to form plaques in a linear configuration over extensor aspects of shins and lower back (Figs 1 & 2)
Few isolated lesions were present over forearms but face and flexures were spared completely. Scarring, milia, excoriations and freshly eroded lesions were observed interspersing these lesions. There were minimal intact flaccid bullae which when pricked exuded clear or hemorrhagic fluid. There were no albopapuloid lesions. All his finger- and toenails were dystrophic or partially lost (Fig3)
Hair, mucosae and other systemic examination showed no abnormality. Routine laboratory investigations including complete blood counts, serum biochemistry, urinalysis, chest x-rays were essentially normal. Histopathlogic examination (Fig 4) of skin biopsy specimen from a shin lesion showed
Hair, mucosae and other systemic examination showed no abnormality. Routine laboratory investigations including complete blood counts, serum biochemistry, urinalysis, chest x-rays were essentially normal. Histopathlogic examination (Fig 4) of skin biopsy specimen from a shin lesion showed hyperkeratosis, mild acanthosis, intact basal cells and sub-basal cleft. There was mild interstitial and perivascular polymorpho-lymphocytic infiltrate in the upper and mid-dermis. Milia were also observed in few sections. He could not afford the cost of immmunofluorescence or molecular studies. Based on the characteristic clinical and histologic features a diagnosis of EBP was made and the patient was counseled for genetic and prognostic implications of the disorder. He was prescribed oral cetirizine (10mg x b.i.d.) and twice daily application of topical Fucibet® cream. When seen after 6 months his clinical condition improved significantly and new blistering had decreased.
Epidermolysis bullosa pruriginosa is a rare type of dystrophic EB and both autosomal dominant and recessive patterns of inheritence have been described 3 . Many sporadic cases have also been reported 2 . The clinical presentation is characterized by intensely pruritic linear lichenified or nodular prurigo-like lesions over extremities, occasional trauma induced blistering, excoriations, milia, nail dystrophy and in some cases albopapuloid lesions over trunk. Age of onset for skin lesions in EBP is very variable. Its onset at birth or during infancy/childhood is usually with mild acral blistering, however, developing first clinical signs in adulthood is not uncommon and can be as late as 40 years of age 3 . The reasons for the delayed presentation in comparison to that of other forms of dystrophic EB are not known. Symptoms in some patients with onset at birth or infancy may also ameliorate to an extent during childhood or adolescence 4 . However, predicting its clinical course is rather difficult as additional genetic, environmental, metabolic, immunologic, hormonal, or other cutaneous or systemic factors which initiate EBP are not well understood. Histologically, hyperkeratosis, mild acanthosis, a cleft/blister at the dermal-epidermal junction and mild to moderate dermal lymphohistiocytic infiltrate are usual but frank blisters are rarely seen. Our patient more or less had all these clinico-pathologic features and apparently inherited the disorder sporadically. The intense pruritus associated with the disorder has been attributed to atopy, iron deficiency, thyroid dysfunction, hyper IgE, abnormal dermal reactivity or
Like other forms of dystrophic epidermolysis bullosa, EBP is also caused by mutations in
As no specific therapies are known, clinical management of EBP is often difficult. Nevertheless, some helpful interventions include topical tacrolimus 9 , systemic cyclosporine 10 , thalidomide 11 or etretinate 2 , cryotherapy 8 and surgical treatment in the form of dermabrasion or excision-grafting 12 . However, new lesions would usually continue to appear. UVB phototherapy tried in one patient had worsened generalized pruritus 2 . Although symptomatic management of pruritus with oral antihistamines or topical/systemic or intralesional corticosteroids, and antibiotics for secondary infection at best seems palliative, treating pruritus aggressively appears to prevent development of other manifestations of the disorder.
Genetic counseling and gene therapy probably remain the most promising approaches. As in other forms of dystrophic EB, a prenatal diagnosis is possible by finding a cleft/blister formation at dermo-epidermal junction by light microscopy or more precisely by electron microscopy in fetal skin biopsy taken at 15 to 18 weeks' of gestation. Similarly, rapid prenatal diagnosis may be possible by using LH 7:2 monoclonal antibody staining of skin samples obtained from 18 weeks' fetus at risk.
Dr. N. L. Sharma Department of Dermatology, Venereology & Leprosy Indira Gandhi Medical College Shimla 171001 (H.P.) India. Tel +91-177-2883404, Fax +91-177 -2658339. E Mail: firstname.lastname@example.org