Pediatric Dermatology: What's your DX?

October 1, 1999

A 3-month-old girl is brought to your office with diarrhea, poor weight gain, and hair loss. She was thriving until a month ago, when her parents said she became chronically irritable and developed loose stools and a scaly rash on her face and in the diaper area.

What's your DX?

PEDIATRIC DERMATOLOGY

Jump to:Choose article section...Discussion
THE AUTHOR 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.

By Bernard A. Cohen, MD

A 3-month-old girl is brought to your office with diarrhea, poor weight gain, and hair loss. She was thriving until a month ago, when her parents said she became chronically irritable and developed loose stools and a scaly rash on her face and in the diaper area. She was breastfed for the first month of life, then weaned to cow's milk­based formula. A week before the visit her parents switched her to a soy-based formula, but she showed no improvement.On examination you find an irritable child with diffuse scaling and crusting around her eyes, nose, and mouth, and in the diaper area. The most severely involved areas show hypopigmentation, and there is some fine scale on the arms, legs, and trunk.

1. What is your differential diagnosis?

2. How would you evaluate this child?

3. How would you treat her?

See "Discussion".

Discussion

This child has the typical history and cutaneous findings of acrodermatitis enteropathica (AEP). Children with AEP develop an erosive diaper dermatitis, diarrhea, and hair loss during the first few months of life.1­4 Weeping, crusted, red patches and erosions also appear in periorificial, acral, and other intertriginous areas. Affected infants are irritable, grow poorly, and are prone to infection and septicemia.

AEP is an autosomal recessive disorder of zinc metabolism.1­4 Affected infants have either decreased or defective zinc-binding protein in the gastrointestinal tract, which leads to zinc malabsorption. Full-term infants have a one-month supply of zinc at birth, so lesions usually appear at 4 to 6 weeks of age. Premature infants have minimal zinc stores and develop symptoms shortly after birth if they are not breastfed or given adequate zinc supplementation. Breast milk contains a compensatory binding ligand that aids zinc absorption. As a result, breastfed infants do not develop clinical symptoms until four to six weeks after weaning.

The differential. Normal infants with other disorders that lead to zinc deficiency develop similar symptoms.4­6 Infectious diarrhea, cystic fibrosis, short bowel syndrome, and inflammatory bowel disease can also result in chronic zinc malabsorption. Children receiving hyperalimentation and special oral formulas without zinc must be given adequate zinc supplementation to avoid complications of zinc deficiency. Recently several children with an AEP­like disorder were described whose mothers had a defect in breast milk zinc concentrations.5 All symptoms cleared after supplementation with physiologic doses of zinc. Similar rashes have been reported in children with biotin deficiency, essential fatty acid deficiency, and urea enzyme cycle defects, which result in amino acid deficiency.

Evaluation. Clinical suspicions can be confirmed by sending blood samples to determine serum zinc levels. However, laboratory workers must take care to avoid contaminating blood samples with small quanitites of zinc from needles, rubber stoppers, and anticoagulants in glass laboratory tubes. Serum alkaline phosphatase (a zinc-dependent metalloenzyme) is also usually decreased.

Treatment. Distinguishing AEP from other zinc deficiency states can be difficult. Unlike other disorders in which zinc deficiency develops as a secondary complication, however, AEP responds dramatically within several days to high doses (5 mg/kg/day) of oral zinc sulfate or gluconate.2,3 Although normal dietary zinc may be adequate for older children with AEP, they need close monitoring for long-term growth and development. Some patients will require lifelong zinc supplementation.

(The next installment of "Pediatric Dermatology: What's your DX?" will appear in January 2000.)

REFERENCES

1. Danbolt N, Closs K: Akrodermatitis enteropathica. Acta Derm Venereol (Stockholm) 1942;23:127

2. Moynahan EJ: Acrodermatitis enteropathica: A lethal inherited human zinc-deficiency disorder (Letter). Lancet 1974;2:399

3. Prasad AS: Zinc: An overview. Nutrition 1995;11 (1Suppl):93

4. Van Wouwe JP: Clinical and laboratory assessment of zinc deficiency in Dutch children: A review. Biol Trace Elem Res 1995;49:211

5. Stevens J, Lubitz L: Symptomatic zinc deficiency in breastfed term and premature infants. J Paediatr Child Health 1998;34:97

6. Bosch AM, Sillevis JH, Van Gennip AH, et al: Iatrogrenic isolated isoleucine deficiency as the acrodermatitis enteropathica-like syndrome. Br J Dermatol 1998;139:488



Molly Frederick. Pediatric Dermatology: What's your DX?. Contemporary Pediatrics 1999;10:27.