CRP5 SPLENIC LESIONS IN PAEDIATRIC MYCOPLASMA PNEUMONIAE INFECTION - AN UNDER-RECOGNISED EXTRAPULMONARY MANIFESTATION

Yinn Tiong, Wei-Nin Kong
Department of Paediatrics, Sibu Hospital, Ministry of Health Malaysia, Sibu, Sarawak, Malaysia

Introduction
Mycoplasma pneumoniae is a small prokaryotic organism characterised by absence of cell wall structure, making it resistant to beta-lactams.  The clinical spectrum of Mycoplasma pneumoniae infection varies widely, ranging from asymptomatic carrier to respiratory symptoms and extrapulmonary manifestations.

Case Description
We reported a 7-year-old girl who presented with 6 days of fever and respiratory symptoms. Her physical examination, inflammatory markers, initial chest radiography and ultrasound findings were consistent with left lobar pneumonia with small parapneumonic effusion. Intravenous Ceftriaxone and oral Azithromycin were initiated but her fever persisted after 4 days of therapy. Repeated ultrasound thorax revealed unchanged left lung consolidation and minimal pleural effusion with incidental finding of multiple tiny ill-defined hypoechoic splenic lesions. Respiratory panel RT-PCR performed later confirmed Mycoplasma pneumoniae infection, she completed a 5-day course of Azithromycin. Her fever resolved on day 13 of illness and a follow-up ultrasound demonstrated improvement of splenic lesions and pleural effusion.

Discussion
Similar rare presentations have been reported in literatures where school-aged children who presented with fever and respiratory symptoms, with confirmed Mycoplasma pneumoniae infection via serological test, exhibited concurrent multiple splenic nodules that improved on follow-up. 
The pathogenesis of extrapulmonary manifestations of Mycoplasma pneumoniae infection involve direct invasion, immune-mediated mechanisms, vascular occlusion and undetermined type. 
In our case, the hypoechoic splenic lesions could represent micro-abscesses or lymphoid hyperplasia. Other possible aetiologies of splenic abscesses eg fungal infection, tuberculosis and melioidosis were unlikely given the resolution of splenic lesions with therapy directed against mycoplasma infection. 
The absence of immunomodulatory therapy in this patient diminished the likelihood of an autoimmune cause.

This case highlights the importance of recognising splenic lesions as part of extrapulmonary manifestations of mycoplasma pneumoniae infection in children.