Endocrine Abstracts

Hashimoto’s thyroiditis is an autoimmnune condition most common in females but can be also found in children with a prevalence of 1.2%. When is associated with hypothyroidism, the growth delay is an important, but late symptom. We present the case of a 12-year-old boy presenting with small height for age (123 cm, <−3 S.D.), important weight gain and fatigue. He was the only child from parents of average height and had normal weight at birth (3300 g). Growth delay was not obvious until 2–3 years ago, when the child remained the shortest in the class, growing at a pace of <2 cm/year. Although with an IQ above average, the patient had mild features of hypothyroidism. Clinical supposition was confirmed by laboratory investigation: fT₄=0.3 ng/ml (normal 0.9–1.9 ng/ml) and TSH=35 mIU/l (normal 0.4–6 mIU/l). Etiological diagnosis of atrophic Hashimoto’s thyroiditis was set by high titers of anti-peroxidase antibodies – 326 U/l (positive when >50 U/l) and small, hypoechogenic, avascular thyroid gland. Therapy with 100 μg/day L-thyroxine and daily rGH injections (0.035 mg/kg per day) was initiated, with spectacular catch-up growth of 30 cm in 2 years (153 cm at 13 years, −0.8 S.D., corresponding to adult parental height). Hashimoto’s thyroiditis is a frequent disease in adult women, but seldomly encountered in prepubertal boys. Normal intellect, relatively harmonious development and the presence of the thyroid gland excluded the hypothesis of an undiagnosed congenital myxoedema in our case. Diagnosis was mainly set by severe growth delay. Catch-up growth under thyroid hormone substitution does not completely restore height handicap in long-standing hypothyroidism, therefore the association of GH therapy may be beneficial, as in our case.