This alert provides updated information for California healthcare providers with regard to testing of pediatric patients for MPX. At this time, we encourage providers to be judicious about MPX virus testing for pediatric patients, including children and non-sexually active adolescents, with no plausible risk of exposure and for whom there is low clinical suspicion for MPX infection.

The decision to test can have a broad impact on the child or adolescent and their family and should therefore be reserved for situations where there is a known or likely exposure, or a clinical presentation very suggestive of MPX infection. The testing process may potentially take several days, resulting in missed school, work, or other activities. It can also be stigmatizing and affect mental health. Further, false-positive test results have been reported, which can happen when testing is performed among people unlikely to have a condition.

The MPX outbreak in California and elsewhere in the U.S. currently remains concentrated among adults who identify as men, and transmission has primarily occurred during sexual and intimate contact with other men. As described by the American Academy of Pediatrics (AAP), the risk of children getting infected with MPX is low. While pediatric cases have been confirmed in the U.S., including in California, they are rare. The AAP recommends testing patients with suspicious lesions if there is a history of close, personal contact with someone who has MPX. This may include living with or being cared for by someone who has MPX or intimate or sexual contact for adolescents who are sexually active.

Rashes and skin lesions are common among children and adolescents and are caused by a variety of infectious and non-infectious conditions, including varicella, herpes simplex virus, hand, foot, and mouth disease caused by enteroviruses, acne, molluscum, scabies, drug-related rashes, allergic reactions, and insect bites.

Coxsackie A-6 (CAV-6), a type of enterovirus, is well known to cause atypical hand, foot and mouth rashes and is circulating in California at this time. Children with eczema are particularly likely to have the atypical rash with CAV-6 and are also at risk for eczema herpeticum. Both of these conditions, as well as varicella, have led to work-ups for MPX in recent weeks in California.

While it is important to consider MPX in any person with compatible symptoms, a rash alone should not necessarily prompt testing. If a provider decides to test for MPX, a plausible risk for exposure should be identified, unless the child or adolescent has one or more lesions that are highly characteristic of MPX.

As mentioned in the August 30, 2022 CDPH MPX CAHAN, if you have a suspect pediatric MPX case, please contact your local health department. We are strongly encouraging consultation and testing of suspect pediatric cases within the California public health laboratory network unless the patient is an adolescent with sexual exposure. It is also very helpful to submit lesion photos if MPX testing is being considered.

For more information, including guidance on evaluating and caring for pediatric patients with possible MPX, see:

Thank you for your continued efforts to keep Californian healthy.