Rare cases in children challenge derms

Vancouver, British Columbia - Dermatologists need to consider the range of characteristics to make a diagnosis of a rare or uncommon condition in children.

"If they have difficulties in making a diagnosis, a dermatologist can refer challenging cases to a pediatric dermatologist," says Bernice Krafchik, M.D., a pediatric dermatologist in private practice in Toronto, Canada, and professor emeritus at the University of Toronto.

Dr. Krafchik describes unusual and rare cases that she has seen in her practice and how she has been able to make an accurate diagnosis and prescribe effective treatment.

Kawasaki disease, look-alikes

One of those cases was Kawasaki disease, or Kawasaki syndrome, where a child presented with peeling lesions in the diaper area, a trait that is common of the disease but not a criterion for diagnosis.

"One of the key criteria is that patients should have a fever for at least five days, plus have four or five other key signs," Dr. Krafchik explains, adding that the condition can be life threatening - 15 percent of patients who are not treated will develop cardiac aneurysms, and approximately 5 percent of patients will develop cardiac aneurysms despite treatment. One percent die, she adds.

Other symptoms of the condition can include conjunctival injection; eruption; peripheral changes, such as palmar and plantar erythema, as well as edema of the dorsa of the hands and feet; lip erythema and scale (lipstick sign); and lymphadenopathy, usually cervical, measuring 1.5 cm.

"The conjunctival erythema can be transient," Dr. Krafchik says. "Patients should be asked if they have had redness of the eyes."

Treatment consists of gamma globulin, 2 g/kg/day, slowly infused intravenously. In addition, 100 mg/kg/day of aspirin is given until apyrexia occurs. Treatment is then tapered to 3 to 5 mg/kg/day for two months. Dr. Krafchik cautions that if patients experience cardiac changes, they will be taking aspirin throughout their lives.

One of the conditions that may mimic Kawasaki disease is mercury intoxication, which is characterized by acrodynia (red palms and soles and red dry lips), hypertension, hyperhidrosis, irritability and pruritus.

Mercury intoxication occurs from broken thermometers, teething powders, poisoned fish and broken phosphorescent bulbs. The condition is treated with chelating agents such as dimercaprol.

Lipoid proteinosis

Dr. Krafchik discusses a case of lipoid proteinosis seen in a 3 year-old boy. The case was caused by an accumulation of lipoid material. She stresses that this very rare condition can be mistaken for either erythropoeitic protoporphyria or hydroa vacciniforme because of the scarring lesions that present on the face and the upper body.

Lipoid proteinosis is inherited recessively. Scarring lesions are present and there is a suggestion of a photosensitivity. The bead-like papules seen around the eyes in adults are not a feature of childhood disease. Lipoid proteinosis may also involve the central nervous system, resulting in seizures, and a magnetic resonance imaging scan may show calcification in the temporal lobes.

The correct diagnosis in this case was eventually prompted during a third visit to Dr. Krafchik's office when the patient's mother indicated the boy had a hoarse voice, which is typical of the disease. Genetic testing for lipoid proteinosis is now available.

Zinc deficiencies

One of the conditions that occurs with more frequency in preterm infants as opposed to their full-term counterparts is a relative zinc deficiency. This occurs when premature babies are breast fed by their mothers - when the baby's metabolic needs increase and the breast milk zinc decreases, the clinical manifestations become evident.

Although clinically similar to acrodermatitis enteropathia, the latter is a recessive disease that requires life-long zinc replacement, whereas relative zinc deficiency disappears when solid food is introduced, according to Dr. Krafchik.

The symptoms of zinc deficiency include hair loss, diarrhea, irritability and infections. Conditions like biotin deficiency and cystic fibrosis may mimic zinc deficiency.