Symptoms of rickets in children

Rickets is a disease with a very high incidence rate among children. This disease is mostly caused by a lack of vitamin D. The most obvious symptom is that children will have bow legs or X-shaped legs. In addition, it can also cause fractures and even deformities. Therefore, parents must pay great attention to rickets. Rickets has different stages of onset, and the symptoms vary at different stages. The following is a detailed introduction to the symptoms of rickets in children.

It occurs in infants under 6 months old, especially infants under 3 months old. Most of them are manifestations of increased nervous excitability, such as irritability, restlessness, sweating, and baldness on the back of the head. There are usually no bone lesions at this stage, and the bone X-ray may be normal or the calcification band may be slightly blurred; serum 25-OH-D3 decreases, PTH increases, blood calcium decreases, blood phosphorus decreases, and alkaline phosphatase is normal or slightly elevated.

As the disease continues to worsen, typical bone changes such as PTH hyperfunction and abnormal calcium and phosphorus metabolism appear. Rickets in infants under 6 months old is mainly characterized by skull changes, soft edges of the anterior fontanelle, thin skull, and a "ping-pong ball" feeling when pressed lightly. After 6 months of age, there may be a ping-pong ball-like feeling around the sutures, but the central part of the frontal bone and parietal bone often gradually thickens. By 7 to 8 months of age, the head shape becomes "square" and the head circumference is larger than normal. The epiphyseal ends swell due to the accumulation of bone-like tissue, and a round protrusion can be felt at the junction of the ribs and costal cartilage along the rib direction. From top to bottom, it is like a string of beads, which is most obvious in the 7th to 10th ribs. It is called rickets beads. In severe cases, blunt round ring-shaped protrusions may also form on the wrists and ankles, which are called bracelets. In children around one year old, the sternum and adjacent cartilage can be seen protruding forward, forming a "pigeon chest" deformity; in children with severe rickets, a horizontal depression forms at the lower edge of the thorax, namely the costophrenic groove or Howe's groove.

When the child sits or stands, the ligaments loosen and the spinal deformity may occur. Due to osteomalacia and muscle and joint relaxation, after the age of one, when the lower limbs begin to bear weight when standing and walking, the femur, tibia, and fibula may bend, forming severe knee valgum ("O" shape) or knee valgum ("X" shape) lower limb deformity. Severe hypophosphatemia may cause muscle sugar metabolism disorders, resulting in whole body muscle relaxation, decreased muscle tone and weakened muscle strength.

During this period, except for a slightly lower serum calcium, changes in other blood biochemical indicators are more significant. X-rays show that the calcification band of long bones disappears, and the epiphyseal ends become brush-like and cup-shaped; the bone is sparse and the cortical bone becomes thinner; there may be diaphyseal curvature or greenstick fractures, and the fractures may have no clinical symptoms.

After treatment or sunlight exposure in any of the above stages, clinical symptoms and signs gradually alleviate or disappear. Blood calcium and phosphorus gradually return to normal, and alkaline phosphatase takes 1 to 2 months to return to normal levels. After 2 to 3 weeks of treatment, the bone X-ray changes improved, with irregular calcification lines appearing. Later, the calcification bands became denser and thicker, and gradually returned to normal.

4. Sequelae

It is more common in children over 2 years old. Due to severe rickets in infancy and childhood, different degrees of bone deformities remain, such as O-shaped legs, X-shaped legs, pigeon chest, etc. There were no clinical symptoms, blood biochemistry was normal, and X-ray examination showed that the skeletal metaphyseal lesions had disappeared.