Rickets in black children beyond infancy in Natal

Abstract

Objective: To determine the clinical spectrum of rickets among black children admitted to King Edward VIII Hospital, Durban. Design: Prospective study of black children with rickets beyond infancy. Setting: Hospital-based population; King Edward VIII Hospital, Durban. Participants: A total of 37 patients, aged 1 - 12 years, were recruited over a 3-year period. None had been on vitamin D or calcium supplementation prior to investigation. Outcome measures: Rickets was diagnosed clinically, radiologically and biochemically (by a raised alkaline phosphatase value of > 350 IU). Gastro-intestinal, hepatic and renal glomerular causes were excluded in all patients using standard clinical and laboratory criteria. Results: Twenty-three patients were diagnosed as having privational rickets. Nine had 25-hydroxyvitamin D (25-0HD) levels of < 10 ng/ml while 14 had levels within the normal range and were suspected of having dietary calcium deficiency. Ten had a phosphopenic variety of rickets; the remaining 4 had healing or healed rickets on the basis of radiological assessment and normal biochemical values. Pain together with difficulty in walking and bowing of the lower limbs were the main reasons for presentation. The main clinical findings were thickened wrists and ankles and rickety rosary (100%), stunting (85%), anterior bowing of lower limbs (70%) and genu valgum (65%). The calcium and vitamin D deficiency group showed a much better clinical, biochemical and radiological response to therapy than the phosphopenic group on follow-up (18 patients). Conclusion: This is the first substantial report on rickets in the older child in Natal, which extends the findings from Transvaal, thereby establishing a recognisable pattern of rickets beyond infancy in South Africa. It draws attention to the common clinical presentations which may alert health professionals to the. presence of this problem. This report demonstrates that the two commonest types are privational rickets (due to calcium and/or vitamin D deficiency) and phosphopenic rickets.

S Afr Med J 1995; 85: 668-672