Skin issues offer clues to underlying gastrointestinal disease.

LA JOLLA, CALIF. -- Certain skin conditions may provide clues to the diagnosis of underlying gastrointestinal disease in children, ranging from epithelial defects, polyposis, or vascular syndromes to autoimmune and allergic disease.

"There are several areas of overlap between the skin and the GI tract," Dr. Magdalene A. Dohil said at a meeting sponsored by Rady Children's Hospital and the American Academy of Pediatrics. If you pick up on these cutaneous signs, you may find an underlying GI disease.

Diseases of the GI tract that commonly involve some form of cutaneous manifestation noted by Dr. Dohil include:

* Epidermolysis bullosa. This condition presents with different degrees of skin fragility and blister formation. The severity "really depends on the underlying molecular defect," said Dr. Dohil, who is a pediatric dermatologist at Rady Children's Hospital, San Diego.

"GI disease in epidermolysis bullosa is extremely common, particularly in the recessive dystrophic type," [in which] almost 80% of children are affected [by dysphagia]. The dysphagia that these children often suffer from can be so severe that they are unable to swallow their own saliva," she said. In fact, the lumen of the esophagus might be obliterated to 2 mm in these patients, whereas a normal lumen is 15-20 mm wide. Other symptoms may include lingual adhesions and microstomia; esophageal disease including strictures, webs, herniation, atony, and pseudodiverticula leading to feeding problems and ultimately protein-energy malnutrition; anemia; and vitamin and mineral deficiency.

* Blue-rubber bleb nevus syndrome (BRBNS). This disease causes multifocal venous malformations in the skin and GI tract. Most cases are sporadic, and histology demonstrates intact epithelium but insufficient smooth muscle. Dr. Dohil described the case of a child who presented with venous malformations on the bottom of the foot, which resembled common warts at first glance. "But when you palpate these lesions, they are soft and compressible," she said.

Common complications of BRBNS include bleeding, chronic anemia, and the need for blood transfusion. Treatment often involves different degrees of surgical intervention including wedge resection, polypectomy, suture ligation, band ligation, and sometimes bowel resection.

"Medical treatment attempts haven't been very successful because these are not proliferative tumors, so we don't expect them to respond to corticosteroids or interferon," explained Dr. Dohil, also of the University of California, San Diego. Capsule endoscopy "facilitates the diagnosis and follow-up of children who need endoscopic intervention and assessment."

* Peutz-Jeghers syndrome. The hallmark skin-related characteristics of this disease include mucocutaneous pigmentation due to melanin deposition. A GI work-up often reveals polyps that may reach into the antral part of the stomach or present throughout the duodenum. These polyps can cause significant morbidity including obstruction, intussusception, pain, hematochezia, and prolapse.

Children with Peutz-Jeghers also carry a high risk of developing invasive carcinoma. In fact, their cumulative risk of developing cancer is 93%, most commonly cancers of the breast, colon, and pancreas, noted Dr. Dohil.

* Cowden's disease. This condition, also known as multiple hamartoma-neoplasia syndrome, causes hamartomas that involve the skin, intestine, breast, and thyroid. It is autosomal dominant and has near complete penetrance by age 20 years. Only 40% of cases will have GI polyposis, but about 80% of cases will present with dermatologic tumors. Consider the diagnosis if you spot more than one trichilemmoma.

* Henoch-Schoenlein purpura. The most common skin presentation is a petechial rash that may develop into multiple raised purpuric lesions. GI symptoms occur in 50%-85% of cases and include abdominal pain, bleeding, vomiting, and bowel edema. The GI effects include mucosal redness, as well as duodenal petechiae and hematomalike protrusions. Most of these changes can be detected with ultrasound.

* Celiac disease. Classic GI symptoms include abdominal distention, weight loss, failure to thrive, and diarrhea. Although serology has facilitated the diagnosis, small-bowel biopsy remains the preferred method. "In these cases you will see villous atrophy, crypt hyperplasia, and lymphocytic infiltrate," Dr. Dohil said. "Such a blunted GI tract doesn't bode well for the absorptive functions that it's intended for."

Dermatitis herpetiformis (Duhring's disease) is considered a cutaneous manifestation. This condition affects about 25% of celiac disease patients and is marked by a pruritic eruption of lesions that may be symmetrical, erythematous, papular, vesicular, or bullous.

These lesions "are fairly uncommon in children, and when they do occur they may not be very distinct," she said. Recently conditions such as xerosis, urticaria, vitiligo, and alopecia areata have been linked to celiac disease. Since they are fairly nonspecific, skin biopsies with direct immunofluorescence and antibody studies of gliadin, endomysium, and transglutaminase are often needed to confirm the diagnosis.

Dr. Dohil reported having no relevant disclosures to make.

BY DOUG BRUNK

San Diego Bureau