M. Pneumoniae May Trigger Inflammatory Skin and Mucous Membrane Lesions in Children

By Marilynn Larkin

December 27, 2019

NEW YORK (Reuters Health) - Inflammatory lesions of the skin and mucous membranes in children and adolescents may be signs of Mycoplasma (M.) pneumoniae infection and should be identified and treated early, researchers say.

Their findings also suggest that mucocutaneous eruptions are associated with more systemic inflammation and morbidity, and a higher risk of long-term sequelae, than infection triggered by other causes, said Dr. Patrick Meyer Sauteur of University Children's Hospital Zurich in an email.

"Therefore," he said, "patients require close monitoring to detect early signs suggestive of potential complications."

"The study builds on our recent work that describes a technique to clarify the role of M. pneumoniae in the setting of community-acquired pneumonia (CAP)," Dr. Sauteur said. In October, his team reported that in contrast to serologic or polymerase chain reaction (PCR) testing, their enzyme-linked immunospot (ELISpot) assay could reliably differentiate M. pneumoniae carriage from active infection. (http://bit.ly/2Myb46B )

More recently, Dr. Sauteur and colleagues analyzed data from their study of the ELISpot assay to assess the frequency and clinical presentation of M. pneumoniae-induced mucocutaneous disease in children with CAP.

As reported in JAMA Dermatology, 152 children (median age, 5.7 years; 55.3% male) were included. Forty-four (28.9%; median age, 8.7; 60% male) tested positive for M. pneumoniae by PCR, and of these, 10 (22.7%) developed mucocutaneous lesions.

All 10 patients with mucocutaneous eruptions tested positive for specific IgM antibody - secreting cells. In the 108 patients with CAP who tested negative for M. pneumoniae with PCR, mucocutaneous disease (maculopapular skin eruptions and conjunctivitis) was observed in three (2.8%).

Manifestations of M. pneumoniae-induced mucocutaneous disease included rash and mucositis (three cases; 6.8%), urticaria (two; 4.5%), and maculopapular skin eruptions (five; 11.4%). Two patients had ocular involvement as the sole mucosal manifestation (bilateral anterior uveitis and nonpurulent conjunctivitis).

Compared with patients without mucocutaneous manifestations, those with skin and mucosal disease had a longer duration of prodromal fever (median, 10.5 days vs. 7.0) and higher C-reactive protein levels (median, 31 mg/L vs. 16); were more likely to require oxygen (five patients vs. one) and hospitalization (seven vs. four); and were more likely to develop long-term sequelae (three vs. none).

Dr. Michele Ramien of the University of Calgary, coauthor of a related editorial, told Reuters Health by email the ELISpot test "would be clinically useful in CAP in general, but especially in the acute situation of a child with severe mucositis - i.e., M.-induced rash and mucositis (MIRM) - and in cases of recurrent MIRM."

"In the acute situation, it could confirm the diagnosis early," she said. "In patients with recurrent MIRM, recurrences could be confirmed as being due to recurrent M. pneumoniae infection versus M. pneumoniae carrier state with a different infectious trigger."

"The clinical implication is that if a patient has a very typical clinical mucocutaneous presentation of MIRM - e.g., mucosal-predominant blistering eruption - and currently available tests for M. pneumoniae (PCR, serology) are positive, then active infection could be presumed and treated," she said.

"As an aside," she noted, "patients with severe mucositis and milder skin blistering should all have a nasopharyngeal or oropharyngeal swab done for M. pneumoniae PCR, which currently is the best test available."

"If M. pneumoniae CAP is suspected based on the presence of a characteristic mucocutaneous eruption like MIRM and signs, symptoms, and radiologic evidence of pneumonia, but serology and PCR are negative, other infections - particularly respiratory infections - should be considered," she said.

"Chlamydophila pneumoniae and influenza B have been reported to cause a MIRM-like eruption," she added. "Our Pediatric Dermatology Research Alliance collaboration has proposed the terminology RIME - reactive infectious mucocutaneous eruption - to include non-M pneumoniae-induced infections. "

SOURCE: https://bit.ly/2ZvyLSf and http://bit.ly/2PYsknL JAMA Dermatology, online December 18, 2019.