SAN DIEGO — Be vigilant about changes to the skin that suggest a diagnosis of Kawasaki disease in infants and children, Jane Burns, M.D., said at the annual meeting of the Society of Pediatric Dermatology.
“We don't want to miss the diagnosis,” said Dr. Burns, who directs the Kawasaki Disease Research Program at the University of California, San Diego. “The clinical signs come and go. We have to rely on history in order to establish the diagnosis in these patients, so a criterion that was present historically is just as valid as a criterion that you can actually see in front of you. Clearly this is dynamic, and different kids evolve in a different kind of rhythm. But historical presence of one of these clinical findings should be taken seriously.”
Skin-related signs of Kawasaki disease (KD) may include:
▸ Bilateral, nonexudative dilation of conjunctival vessels. This presents as a dry eye with dilated vessels and limbal sparing. “The reason that we see the limbus so clearly is that there is no edema in the conjunctiva,” she explained. “This is not conjunctivitis. That is a misnomer. This is vessel dilatation, probably mediated by cytokines and other factors. These are simply dilated vessels. We've done conjunctival biopsies on these children and that's what we see.”
She added that the condition is marked by no tearing, no superficial infection or involvement of the epithelial cells. “This is not like adenovirus,” she said. “There is no inflammation on the outside of the eye.”
▸ Erythema of lips.
▸ Classic “strawberry tongue.” This presents as a sloughing of the filiform papillae because of the systemic inflammatory process and persistence of the fungiform papillae, which gives the appearance of strawberry “seeds.” Strawberry tongue is also associated with streptococcal and staphylococcal diseases. “It's not pathognomonic for KD, but it's a helpful finding when you see it,” Dr. Burns said.
▸ Accentuated groin rash. This symptom is seen in about half of KD patients. “Pediatricians frequently mistake this for diaper dermatitis,” she said. “Desquamation occurs during the acute phase of the disease.”
▸ Unilaterally enlarged lymph node. Fewer than 40% of KD patients will present with this symptom. “Generally it's a unilateral anterior cervical node, usually involving the jugular digastric node,” Dr. Burns said. “These are the patients that get referred to ENT. Hopefully they recognize it, but unfortunately many times these kids are treated for bacterial lymphadenitis. Then they develop a rash. The rash is thought to be related to the antibiotic therapy, and [the rash persists] until someone recognizes what's going on.”
▸ Micropustular rash with petechiae. Although this rash only presents in about 15% of KD patients, it's very specific for the disease. It typically presents over the buttocks and sometimes on the extensor surfaces of the arms.
▸ Diffuse erythema of the palm. “There is no pattern to the erythema,” Dr. Burns said of this symptom. “It comes and goes during the course of the disease.”
▸ Diffuse erythema of the sole.
▸ Swelling of the hands and feet.
Eczema is another complication that affects children with KD. “They may present with their first exacerbation of eczema in the convalescent period of the disease,” she said. “Then there's psoriasis. This can happen within 2 months of the onset.”
Although there are no specific diagnostic tests for KD, Dr. Burns noted that nonspecific indicators of inflammation—such as C-reactive protein and sedimentation rate—are elevated. She added that gamma-glutamyl-transferase “is a very useful marker of hepatobiliary dysfunction [in KD patients], not typically seen in a lot of other viral infections.”
For a diagnostic algorithm of Kawasaki disease, Dr. Burns suggested referring to the following journal article: Circulation 2004;110:2747–71.