Idiopathic isolated central hypothyroidism associated with congenital ichthyosiform desquamans erythrodermia

Abstract

We report an idiopathic isolated central hypothyroidism,supposed as consequence of TRH deficiency, in a child with congenital icthyosiform desquamativa erythrodermia,first seen by us at the age of 10y. D.V. was born preterm, vaginally, after a referred uncomplicated pregnancy. Skin lesions appeared during the first days of life and stunted growth and feeding problems within the first months; intellectual development appeared as normal and a normal sexual development started at the age of 12 1/2y. Arginine, insulin,TRH and LHRH tests excluded GH,PRL,ACTH,FSH or LH deficiency. Two TRH tests showed Δ TSH=3.7 and 3.3 μU/ml (n.v.=12.5±4.0) with basal TSH values =1.2 and 0.9 μU/ml respectively; T4 and T3 basal levels were 6.6 μg/dl(8.9±2.2) and 123.3 ng/dl(163.4±29.7) respectively; Δ T3 was 33.7 ng/dl (65±38). Radioimmunological assays were performed in triplicate (Biodata,Milan).Electrolytes,karyotype,skull radiography were normal A thyroidal therapy (130 mg/day of desiccated thyroid) was started when he was 13 4/12y.old and after 3y.variations of clinical parame ters were:delay of height and bone age in respect to chronological age from-6 to -4y. and from-5 to-2 1/2y.respectively;height velocity grew from 4.8 to 10.0cm./y.;skin lesions did not improved. T3 serum reduced increase supports a TRH more likely than a TSH deficiency.