PEDIATRIC DERMATOLOGY

What's your Dx?

By Muhammad Waseem, MD, and Bernard A. Cohen, MD

At several hours of age, this infant developed large, flaccid blisters on the diaper area. Over the next day, blisters spread to the hands, feet, and face, particularly the area around the mouth. Despite a few blisters in his mouth, he fed vigorously from a bottle and appeared well.

1. What is the most likely diagnosis?

2. What is the differential diagnosis of blistering disorders in the newborn?

3. What is the management?

4. How would you counsel the parents?

The diagnosis: Epidermolysis bullosa

The large flaccid blisters that developed over areas of trauma in this otherwise healthy newborn most likely represent epidermolysis bullosa (EB). Three major types of EB have been described, based on the ultrastructural location of blisters.^1-3

• In EB simplex, or epidermolytic EB, cleavage of the skin occurs within the epidermis, generally through the basal cells. Blisters usually heal without scarring.

• In dystrophic EB, or dermolytic EB, blisters form in the dermis and heal with scarring.

• In junctional EB, blisters are characterized by cleavage in the lamina lucida within the basement membrane zone, or junction between the epidermis and dermis. Junctional EB blisters usually heal without scarring, but atrophy and scarring can occur with recurrent blistering at the same site.

Clinical presentation of the three types varies with inheritance and distribution of blisters.^1-3 In EB simplex, blistering of mucous membranes is usually absent or minimal. Skin lesions, which often heal quickly, may be localized to the hands and feet or occur in a more generalized distribution.

The expression of dystrophic EB varies widely. Localized dominant variants tend to be mild, with little involvement of mucous membranes. Generalized recessive forms are associated with failure to thrive, corneal scarring, severe dental disease, esophageal stenosis, nail dystrophy, and cutaneous scarring with fusion of fingers and toes.

Although junctional EB may be mild and behave like generalized EB simplex, severe variants (such as autosomal recessive Herlitz variant) are associated with widespread skin and mucous membrane involvement, failure to thrive, recurrent infection, sepsis, and death, usually during the first year of life.

Course. Although blisters may appear at or shortly after birth, onset may be delayed in some variants until later childhood or adolescence, when an increase in physical trauma associated with participation in sports or military training results in blister formation. In children who do not have a family history of EB, it may be difficult to determine the course in the neonatal period even after the ultrastructural defect is known. Healthy, vigorous newborns with junctional EB may develop severe disease, with a downhill course and early death. In newborns with localized dystrophic EB, blisters on the feet may go into remission, leaving asymptomatic scars. The physician should therefore be reassuring and postpone discussion of prognosis for two to four months.

Evaluation. Initial evaluation should include a thorough physical examination, family history, and skin biopsy for routine pathologic analysis and electron microscopy. Gene markers for selective variants are also available, and will be useful for genetic counseling and subsequent prenatal diagnosis.⁴

Differential. The differential diagnosis of blistering disorders in the newborn includes a number of innocent conditions as well as potentially life-threatening ones. The vesicles of herpes simplex virus are usually small (2-4 mm), uniform, and clustered. A Tzanck smear, culture, or skin biopsy can exclude the diagnosis. Pustules and necrotic vesicles associated with bacterial and fungal infection can be diagnosed quickly with a Gram stain and culture. Miliaria crystallina, benign pustular eruptions of the neonate (erythema toxicum, transient pustular melanosis, eosinophilic pustular folliculitis), the inflammatory phase of incontinentia pigmenti, and acne can be excluded by clinical presentation, course, and histologic study if necessary.

Treatment. In this infant with autosomal recessive dystrophic EB, aggressive measures were taken to clean and protect the skin.⁵ Gentle handling of the skin is mandatory; rectal temperature checks, applications of adhesives, and other irritants should be avoided. His parents were trained to change dressings daily after gentle soaking and debridement with tepid water. Petrolatum is advised to protect clean areas, and topical antibiotic ointment should be applied to crusted or purulent lesions. Oral antibiotics are reserved for episodes of localized cellulitis and widespread impetiginization.

In this child, recurrent blistering in the mouth resulted in poor feeding. The increased protein and calorie demand of healing blisters resulted in failure to thrive. He had a gastrostomy placed and is slowly gaining weight.

The informed pediatrician and dermatologist can coordinate a multidisciplinary approach to management of EB.^5,6 Children with this variant require ongoing ophthalmic evaluation for recurrent ulcers of the cornea, keratitis, and corneal opacities; dentistry for recurrent oral erosions, gingivitis, and dental caries; gastroenterologic evaluation for recurrent oral and esophageal blistering and stricture formation; and physical therapy and plastic surgery for scarring of the hands and feet that can result in fusion of fingers, toes, and other joints.

REFERENCES

1. Fine JD: Epidermolysis bullosa, in Arndt KA (ed): Cutaneous Medicine and Surgery: An Integrated Program in Dermatology. Philadelphia, Pa., WB Saunders, 1996, pp 635-645

2. Fine JD, Eady RA, Bauer EA, et al: Revised classification system for inherited epidermolysis bullosa: Report of the Second International Consensus Meeting on diagnosis and classification of epidermolysis bullosa. J Am Acad Dermatol 2000;42:1051

3. Marinkovich MP: Update on inherited bullous dermatoses. Dermatol Clin 1999;17:473

4. Uitto J: Molecular diagnostics of epidermolysis bullosa: Novel pathomechanisms and surprising genetics. Exp Dermatol 1999;8:92

5. Schober-Flores C: Epidermolysis bullosa: A nursing perspective. Dermatol Nurs 1999;11:243

6. Korman NJ: New and emerging therapies in the treatment of blistering diseases. Dermatol Clin 2000;18:127

DR. WASEEM is a fellow in Pediatric Emergency Medicine at Lincoln Medical and Mental Health Center, Bronx, N.Y.

DR. COHEN, who serves as Section Editor for Pediatric Dermatology: What's your DX?, is Director, Pediatric Dermatology and Cutaneous Laser Center, and Associate Professor of Pediatrics and Dermatology at Johns Hopkins University School of Medicine, Baltimore. He is a Contributing Editor for Contemporary Pediatrics.

 

Bernard Cohen. Pediatric dermatology: What's your DX?. Contemporary Pediatrics 2001;4:37.