Pediatric skin conditions can present in puzzling ways

Denver - In discussing tropical skin ailments that can affect children, Scott A. Norton, M.D., presented cases at the 72^nd Annual Meeting of the American Academy of Dermatology using a “Jeopardy” format that required students in the audience to frame their diagnoses as questions based on the symptoms outlined:

Monkeypox - The clues: “A Congolese child had one week of fever, chills, headache, backache, and then developed a rash over several days.” During this time, the rash progressed from scattered lesions into a confluent mass of lesions that virtually covered the child's body.

The question: What is monkeypox? Dr. Norton says, “Smallpox doesn’t exist in real life; monkeypox does. Monkeypox, smallpox, cowpox and vaccinia are all members of the true Orthopoxvirus family. Infection with one will probably confer cross-immunity for life to the others.”

The child featured in this case likely contracted monkeypox from eating bushmeat, Dr. Norton says. Conversely, he adds, a recent outbreak in Wisconsin stemmed from Americans’ fascination with exotic pets; namely, the giant Gambian pouched rat.

Scabies - The clues: Pruritic penile papules. “Scabies is nearly ubiquitous in some parts of the world, with perhaps a 70 percent to nearly 100 percent prevalence,” Dr. Norton says. It would be overly bold to say that dermatologists always know what it looks like, he adds. “In different people, it can look like a wide range of things. Especially in kids, scabies can be extremely polymorphous - you don’t often see the classic burrows or distribution (wrists and webs of the fingers and toes).”

Because scabies provides a portal for staphylococcal and streptococcal infections and exerts a huge economic impact worldwide, the World Health Organization has labeled it a neglected tropical disease.

Phytophotodermatitis -The clues: Brown streaks on sun-exposed skin. Phytophotodermatitis can appear - somewhat mysteriously, to sufferers - after a trip to the tropics, Dr. Norton says. “It’s a phototoxic reaction to the juice or sap of certain plants. We most commonly see it associated with limes.” Not cultivated California or Arizona limes from mainstream groceries, he says, but wild limes from areas such as Mexico and Jamaica that reach stateside ethnic grocers. Unlike these limes, Dr. Norton says, large-scale commercially cultivated limes contain little of the furanocoumarins responsible for the reaction.

“I see about three cases a year on Ocho de Mayo,” he says. At Cinco de Mayo celebrations, he explains, revelers of all races may squeeze these limes into their margaritas, dripping juice onto their hands, arms or legs. Following sun exposure, the brown streaks - the result of chemical burns - appear in areas where partiers didn’t wash off the juice.

Dr. Norton is chief of dermatology at Children’s National Medical Center, Washington.