Epidemiological and clinical characteristics and the approach to infant chickenpox in primary care

Abstract

Chickenpox is not common in the first year of life (infant varicella) and there is a lack of data on its presentation, especially in primary care. A year-long observational study (July 2015-2016) carried out by a research network of primary care pediatricians throughout Spain.Two hundred and sixty-four pediatricians gathered data from 358 cases of clinically diagnosed chickenpox in infants. The illness was considered mild in 78% of infants < 7months compared to 65% in those aged 7 to 12months (p = 0.0144). Fever (46%) was present in 35% of children ≤ 6months compared to 55% in older children (p = 0.0005). The number of skin lesions was > 50 in 35% of children ≤ 6months old compared to 47% in > 7months (p = 0.0273). From the 2% of hospitalized children 86% were younger than 7months. Oral antiviral treatment was given in 33% of cases ≤ 6months compared to 18% in older patients (p = 0.0023). Doubts about administering the chickenpox vaccine at a later date were expressed by 18% of pediatricians.Conclusion: Chickenpox is considered benign, having a mild effect on most infants. There is less clinical effect in infants ≤ 6months although this age group is hospitalized more and is prescribed more antiviral treatment. There are doubts among pediatricians about the subsequent need for vaccination. What is Known: • Chickenpox is uncommon and of uncertain evolution in the first year of life • Hospital admissions for chickenpox are more frequent in the first year of life What is New: • The course of chickenpox in the first year of life is mild, especially in infants younger than 7months despite the fact they are hospitalized more and are treated more frequently with antivirals. Antivirals are prescribed to 1 in 4 children with chickenpox under 12months of age. • Almost 50% of pediatricians recommend a subsequent vaccination against chickenpox especially if it occurs in the first 6months of life.