Chronic autoimmune thyroiditis (CAT) is multifaced disease. Its incidence has increased dramatically over the past few decades afflicting up to 2% of the general population. CAT as autoimmune disorder results from complex interplay of genetic, environmental and endogenous factors. In nonendemic goitre areas, CAT is the most common cause of acquired hyothyroidism.
Unlike overt goitrogenic form of disease, atrophic one remains hidden or misdiagnosed for years.
Some children expirience all thyroid dysfunction types during natural course of the disease; mild hyperthyroidism at diagnosis (hashitoxicosis), euthyroid state, and gradual progression from subclinical to overt hypothyroidism.
The clinical manifestations of acquired hypothyroidism (AH) in childhood differ from those in adults. The classic manifestation also occur in children, but are not so prominent. Instead, the most important sign of AH in childhood is growth failure. Weight tends to increase and in most instances weight for age is greater than height for age. The retardation of bone age in AH usually equals or exceeds the retardation in linear growth. Pubertal disorders: delayed, or even precocious puberty are always present.
Another intriguing form of dysfunction in CAT could be the subclinical hypothyroidism with mixed signs of hypo and hyperfunction (autoimmune dysthyroidism). Thus, clinical features do not always correspond to hormonal status. The reasons for diagnostic pitfalls, because of clinical ambiguity are challenging for pediatricians and endocrinologists.