Incidence of thyrotoxicosis in childhood: a national population based study in the UK and Ireland.

OBJECTIVE

To measure the UK and Ireland incidence of childhood (<15 years) thyrotoxicosis and to describe the presenting features.

CONTEXT: Incidence data on thyrotoxicosis in childhood are not available for the UK and Ireland. Recent studies have reported an apparent increase in cases in Europe.

DESIGN

A national prospective surveillance study for 12 months from September 2004, co-ordinated by The British Paediatric Surveillance Unit (BPSU).

PATIENTS AND MEASUREMENTS: All paediatricians across the UK and Ireland were requested monthly to report new cases. Details of presenting features were then obtained by questionnaire.

RESULTS

One hundred ten cases of acquired childhood thyrotoxicosis were identified in the UK and Ireland. The incidence of acquired thyrotoxicosis was 0.9 per 100,000 <15 years olds in the UK and Ireland, (95% CI: 0.8-1.1). Autoimmune thyrotoxicosis accounted for 96% of cases. There was an increasing incidence with age in each sex. Females have a significantly higher incidence than males in the 10- to 14-year age group. A variety of presenting symptoms were reported: weight loss (64%), fatigue/tiredness (54%), change in behaviour' (50%) and heat intolerance (47%). 4.5 % cases were asymptomatic. The commonest signs were goitre (78%) and tremor (58%). There were no cases of thyroid storm.

CONCLUSIONS

This national population survey defines the incidence of thyrotoxicosis in children in the UK and Ireland during 2004-2005, which was lower than expected in comparison with other European studies. The survey illustrates contemporary presenting characteristics of the disease.