Hypothermia in a 6-Week Infant-an Atypical Presentation of Multisystem Inflammatory Syndrome (MIS-C)

Introduction

MIS-C is a rare complication of covid-19. The definition across the organizations is based on 6 principle elements: pediatric age, persistence of fever, presence of laboratory markers of inflammation, manifestation of signs or symptoms of organ dysfunction, lacking an alternative diagnosis, and a temporal relation to COVID-19 infection or exposure [1]. We describe an atypical case of MIS-C with myocarditis in a 6-week-old infant presenting with hypothermia rather than fever.

Case Report

Six weeks old, exclusively breast-fed, male born out of nonconsanguineous marriage to COVID RT-PCR negative mother with uneventful birth history presented with sudden onset of excessive crying, refusal to feed, bluish discoloration of extremities. Child was extremely cold to touch. There was no history of fever, vomiting, seizures and breathing difficulty. On admission, the child had inconsolable cry, erythematous rash over the body and mottling over extremities. On examination, his core(rectal) and peripheral temperature was 31 degree Celsius with heart rate of 190/min, respiratory rate of 74 /min, capillary refill time 8 sec, poor peripheral pulses, blood pressure 104/59 mmHg (50th centile) and saturation of 87% on room air. Systemic examination showed muffled heart sounds with hepatomegaly. Chest auscultation revealed normal breath sounds. Child was immediately put on warmer and humidified high flow oxygen. Shock was managed as per the standard protocol [fluid bolus followed by ionotropic support (adrenaline and nor adrenaline)]. Bedside echocardiography was done which showed left ventricular dysfunction (ejection fraction 30%) with pericardial effusion. In view of catecholamine resistant shock iv hydrocortisone infusion was started. After 8 hours, peripheral temperature improved to 37 degree Celsius with better perfusion. In view of myocarditis, immunoglobulin was admistered (1gm/kg). Blood investigations showed no evidence of sepsis although inflammatory (including cardiac) markers were high (Table 1). Due to outbreak situation and baby exclusively breast fed, COVID-19 RTPCR and IgG antibody tests were done both for the baby and the mother which showed negative RT-PCR but positive IgG titres 38 AU/ml (done by CLIA method: normal range <12AU/ml) in baby and both were negative in mother. Child gradually improved on supportive treatment with downward trends in inflammatory markers. Ionotropic support was tapered and stopped by day 3. Child got discharged on cardiac support therapy (Enalapril and Aldactone) and is doing well in follow up.

  

    
Investigations 
    
Normal    values 
    
Da- 1 
    
Day-4    (post immunotherapy) 
  
  

    
Hemoglobin    (g/dl) 
    
9-13 
    
10.5 
    
9.8 
  
  

    
*TLC    (per-ul) 
    
4-10 
    
8700 
    
9800 
  
  

    
†ALC    (per-ul) 
    
1-3 
    
3820 
    
3470 
  
  

    
Platelets    (per-ul) 
    
15000-450000 
    
32700 
    
35400 
  
  

    
‡hsCRP    mg/dl 
    
<0.1 
    
35 
    
13 
  
  

    
§ESR    mm 1st hr 
    
0-10 
    
70 
    
24 
  
  

    
Procalcitonin    (ng/ml) 
    
<0.5 
    
0.4 
    
0.1 
  
  

    
Lactate    (mmol/L) 
    
5 
    
2.1 
    
1.5 
  
  

    
||AST    (U/l) 
    
<35 
    
85 
    
43 
  
  

    
¶ALT    (U/l) 
    
<35 
    
78 
    
38 
  
  

    
Fibrinogen    (mg/dl) 
    
150-400 
    
297 
    
305 
  
  

    
Ferritin    (ng/ml) 
    
23.9-336.2 
    
678 
    
435 
  
  

    
D-dimer    (ng/ml) 
    
0-200 
    
301 
    
290 
  
  

    
Troponin-I    (ng/ml) 
    
0.00-0.07 
    
0.12 
    
0.05 
  
  

    
**Pro-BNP    (pg/ml) 
    
125-450 
    
3541 
    
878.9 
  
  

    
Cortisol    (random) ug/dl 
    
<10 
    
22.9 
    
25.8 
  
  

    
Blood    culture 
    
Sterile 
    
Sterile 
    
Not done 
  
  

    
COVID    IgG (AU/ml) 
    
<12 
    
38 
    
Not done 
  
  

    
2D    ECHO 
    
Ejection Fraction (EF) >55% 
    
LV dysfunction, EF-30%,    Pericardial effusion 
    
EF-45%, Pericardial effusion 
  
  

    
*TLC-Total Leucocyte Counts, †ALC-Absolute    Lymphocyte Counts, ‡hsCRP-High Sensitive C Reactive Protein, §ESR-Erythrocyte    Sedimentation Rate, ||AST-aspartate aminotransferase, ¶ALT-Alanine    Transaminase, Pro-BNP-Pro B-Type Natriuretic Peptide. 
  

Table 1: