Transient hyperphosphatasemia in a toddler with COVID-19 infection: A case report and literature review

Abstract

BACKGROUND

Transient hyperphosphatasemia (TH) is a condition characterized by elevated serum alkaline phosphatase (ALP) in the clinical setting with no evidence of bone or liver disease among children under the age of 5. Typically, it will resolve spontaneously in a few months in the majority of cases. TH has been found to be associated with viral infections. Two cases of TH associated with coronavirus disease 2019 (COVID-19) infection in toddlers have been previously reported.

CASE SUMMARY

A previously healthy 2-year-old boy presented with fever and positive real-time polymerase chain reaction for COVID-19. Prior to his illness, the patient had been in close contact with his grandfather, who later developed COVID-19. The physical examination on admission was unremarkable. He remained asymptomatic throughout 7 d of hospitalization. On the 5^th day of his illness, blood tests showed markedly elevated serum ALP (4178 U/L). Results from the simultaneous testing of the remaining liver profiles and metabolic bone panels were normal. Two months after discharge from the hospital, the patient continued to thrive well. The skeletal surveys revealed no significant abnormalities. The serum ALP declined into the normal range adjusted for his age. This evidence is consistent with the diagnosis of TH.

CONCLUSION

TH can occur in COVID-19-infected toddlers. Serial measurements of ALP levels have been shown to gradually decline into the normal range within a few months. Therefore, being aware of this transient abnormality will help clinicians to avoid additional unnecessary investigations.

Keywords: Alkaline phosphatase; Coronavirus; Pediatric endocrinology; Case report

Core Tip: Transient hyperphosphatasemia (TH) is an unrecognized condition among children under the age of 5. The only abnormality demonstrated is markedly elevated serum alkaline phosphatase (ALP) without evidence of bone or hepatic disease and spontaneous resolution occurring in several months. Numerous reports have identified various viral infections as contributing factors to the etiology of this condition. TH should be considered in coronavirus disease 2019 -infected toddlers exhibiting isolated high serum ALP. Awareness of this condition will help to avoid unnecessary investigations.