Rickets is a medical condition that affects infants and children. A related disorder that affects adults is known as osteomalacia. Rickets was very common in the past but in developed countries, it is a rare condition. However, cases of the disease can still be found in developing countries.
Definition & Facts
Rickets is a disease that affects the bone development in children and is most commonly caused by a lack of vitamin D and calcium in the diet. The vitamin D deficiency occurs before any visible signs are apparent and before the patient is presented for a physical examination.
A Greek physician Soranus Ephesus in Rome first documented rickets as early as the first and second centuries. Soranus reported deformities of bones in young children. However, it was not defined to be a medical condition until 1645 when Daniel Whistler gave the first description of the disease.
After a major increase in cases in England, Francis Glisson in 1650 released a study of the disease. Rickets was so common in England it became known as the English Disease. The disease was linked to poor environment and diet during the Industrial Revolution as smog blocked out sunlight.
Before 1915, it was estimated that 85 percent of children in industrial developing areas of Europe and America had rickets. It was not until 1918 that Kurt Huldschinsky demonstrated that rickets was treatable with ultraviolet lights and then in the 1920’s researchers found that cod liver oil and fortified cow's milk could prevent the disease. It was after these discoveries that rickets was eradicated in the countries of Europe and North America.
Symptoms & Complaints
- Pain in the affected bones, which can cause the child to walk differently or be reluctant to walk.
- Skeletal deformities such as the widening of the ankles, wrists, knees, bowed legs, soft skull bone and bending of the spine can occur.
- Dental problems of weakening tooth enamel, increased risk of cavities and a delay in the teeth coming through the gums.
- Reduced and abnormal growth and development in the bones.
- Fragile, soft bones that makes them weaker and more susceptible to fractures.
- Hypocalcaemia, low levels of calcium in the blood which can cause muscle cramps.
The primary cause of rickets is a lack of vitamin D and calcium in the body. Both are crucial for the development of healthy bones. A child with a poor diet lacking in both is likely to develop rickets. Forms of rickets can be genetic and inherited by the child. However these forms are rarer.
Hypophosphatemia is a genetic form of rickets that affects how the kidneys and bones deal with phosphate. The condition is caused by a mutation in the PHEX gene located on the X chromosome, which has to be passed down by the child’s parents. X-linked hypophosphatemia is the most common genetic form with one in 20,000 newborns being affected, but other forms have only been identified in a small number of families.
Rickets can occasionally be developed from other conditions. Conditions including kidney, liver and intestinal issues, which affect the absorption of vitamins and minerals into the blood and body. Individuals with darker skin are at higher risk, as they need higher levels of sunlight to produce enough vitamin D. Living in a climate with little sunlight exposure or not getting enough sunlight to produce vitamin D can cause rickets.
Diagnoses & Test
Doctors will often perform a physical examination of children suspected of having rickets. The tenderness and pain in the bones are checked by lightly pressing on the bones. Blood tests are taken to measure the level of calcium and phosphate in the blood, which can confirm the diagnoses. X-rays are taken to check for bone deformities, which are a primary symptom of the disease.
In a small number of rare cases, a bone biopsy is done. This process involves as a very small section of bone being removed and the biopsy sent to a laboratory to be tested and analyzed for rickets. Arterial blood gas tests may be taken to check the level of oxygen and carbon dioxide in the blood. Alkaline phosphatase (ALP) blood tests are done to verify the level of the protein found in the bones as they are meant to have a high amount present. Low results are a sign of rickets.
Treatments & Therapy
Rickets is commonly treated by increasing the intake of vitamin D and calcium. The intake can be increased by eating foods that are rich in both. Foods with high calcium include oily fish, spinach, soybeans, kale and white beans. Foods that have high levels of vitamin D are cheese, egg yolks, fatty fish, and liver.
Taking daily vitamin supplements is another common treatment. It is recommended by the National Academy of Sciences that infants and children with inadequate sunlight exposure take a vitamin D supplement. There is a vitamin D injection available for once a year for children who cannot take the supplements orally or who have intestinal or liver disease.
Increasing the amount of time outside is a treatment as sunlight is a source of vitamin D. Repositioning, and bracing of bones may occur to reduce and correct any skeletal deformities and in some cases, surgery may be required for correction.
Prevention & Prophylaxis
Having enough sunlight is also important, with ten to fifteen minutes of exposure a day while the sun is at its strongest between 11:00am to 3:00pm several times a week.