Child homicide or natural death? A case report of unexpected death of unusual asymptomatic acute laryngotracheobronchitis

Introduction

Although asphyxia is commonly encountered in forensic practice, finding out the ultimate cause of death is still a challenge to medical examiners. Unexpected deaths due to asphyxia without obvious injuries sometimes make the manner of death, such as smothering with a soft pillow versus fatal respiratory obstruction, even more difficult to determine. We present a case of a 2-year-old boy who died unexpectedly at home. In the preliminary investigation, his mother was suspected to have killed him. However, the autopsy and pathological findings revealed that the boy died of an unusual case of asymptomatic acute laryngotracheobronchitis (LTB).

Case report

A 2-year-old boy was found dead on the bedroom floor, and the police were summoned by a family member. According to the police investigation, on that day at 8 pm, after a fierce quarrel with the boy’s mother at the maternal grandparents’ home, the boy’s father left in anger. At around 9 pm, the mother and the boy went out for a walk, and told the grandparents that they would be back soon; however, they did not return. At around 10 pm, the maternal grandparents received an emergency call from the boy’s mother that the boy was unconsciousness at home. The maternal grandparents arrived quickly, and an ambulance was summoned. The paramedics arrived at 10.30 pm and found the boy in cardiopulmonary arrest. The resuscitation attempts failed, and the boy was pronounced dead at the scene. The boy’s father was not informed until the boy was dead. He was highly suspicious that the mother had killed the boy. Therefore, the case was reported to the police.

The boy’s medical history was significant for two episodes of febrile seizures in the past year, which were characterized by fever, convulsion, foaming in the mouth, and disturbance of consciousness. In addition, 3 days earlier, the boy was in a low mood and complained of generalized weakness, but no coughing was noted at that time. All the family members believed the boy had been healthy prior to death. A medicolegal examination was requested to find out the cause of death.

A complete medicolegal autopsy was then performed. The body was 99 cm in length and weighed 14.25 kg. External examination of the body revealed a well-developed and normal boy without any obvious injuries. Cyanosis was noted in the lips and fingernails. No petechia was observed on the conjunctivae or sclera. Furthermore, no adverse findings were found in the inner lips and cheeks.

The internal examination showed the larynx was markedly edematous, and foaming was seen in the vestibule of the larynx. The vestibular and vocal folds were pale and swollen, which caused mild narrowing of the upper airway. No foreign body or secretions were found in the larynx and trachea (Figure 1). The layer-by-layer and posterior neck exams were unremarkable. OPEN IN VIEWER

The histopathological examinations showed mild edema with inflammatory infiltration in the submucosa and mucosa of the larynx, mainly affecting the area from the aryepiglottic to vestibular folds. Lymphocyte and monocyte infiltration in the mucosa and submucosa was also noted in the trachea and bronchus (Figures 2 and 3). Although inflammation involving the bronchiole near the pulmonary hilum as well as foci of mild inflammation in the interstitial area was found, this did not meet the diagnostic criteria of pneumonia. The lungs showed extensive edema and congestion with mild emphysema. In addition, the results of toxicological tests were negative. OPEN IN VIEWER

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Figure 3.

Inflammation in the mucosa and submucosa of the bronchia (H&E stain; Original magnification ×100).

Discussion

In this case, no trauma or findings indicating suffocation or strangulation were evident. The significant pathological findings of inflammatory infiltration affecting the larynx, trachea, and bronchi demonstrated the diagnosis of acute LTB which led to unexpected death. LTB is histologically characterized by inflammatory infiltration mainly affecting the subglottic respiratory tract.^1–3 Inflammation is usually restricted to the larynx, trachea, and bronchi. Laryngeal edema and inflammation cause the life-threatening obstruction of the upper respiratory tract, and complete closure of the subglottis may occur within a few hours. ⁴

LTB usually occurs in children aged from 6 months to 6 years, peaks during the second year of life, and is most frequently found in the male sex.^5,6 Virus-mediated respiratory infection is mainly responsible for most LTB. Abrupt onset of barking cough, hoarseness, inspiratory stridor, and respiratory distress are highly suggestive of LTB. ⁷ Symptoms of LTB may worsen at night and when the child is agitated, ⁸ and symptoms also vary from child to child based on host factors, such as immunity and the anatomy of the subglottic space. ³ However, atypical or even asymptomatic LTB are rarely clinically reported. In the present case, the little boy presented an unusual acute LTB without significant premonitory symptoms that caused the sudden death. This indicates that clinical manifestations may be unremarkable in young patients with acute LTB, and that it can lead to sudden unexpected death in a very short time.

Cases involving deaths of children are always of great concern for the whole family. This case shows that some diseases in children may present with atypical signs and can be easily ignored by the parents. However, these diseases rapidly progress and may lead to sudden death. Deaths from LTB are seldom reported in the field of forensic medicine. It is difficult to determine by gross examinations; therefore, histological examinations must be performed to make a precise diagnosis. In addition, even though microbiological studies were not conducted in the present case, we still strongly suggest that microbiology and virology sampling should be standard procedure in such pediatric deaths. This not only confirms the cause of death but also provides data for further studying of LTB.

Medical examiners should pay close attention to cases in children with suspected LTB. Because severe LTB without symptoms is extremely rare, the lack of symptoms may actually reflect neglect and the lack of parental skills. Therefore, it is also necessary to strengthen parents’ knowledge of pediatric disease, increase awareness of premonitory symptoms, and reduce mortality.