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Rickets and osteomalacia: cause, symptoms, therapy

by Josephine Andrews
Published: Last Updated on 234 views

Rickets or osteomalacia is a bone disease. Due to a disturbance in the bone metabolism, too few minerals are stored in the bones – the bones become soft. The most common cause is a vitamin D deficiency. How do you recognize rickets? How is bone disease treated? Can rickets be prevented? You can find out all about this in the following article.

ICD codes for this disease:

ICD codes are internationally valid codes for medical diagnoses. They can be found, for example, in doctor’s letters or on certificates of incapacity for work.

E83 E55 N25 M83

quick overview

  • What is rickets or osteomalacia? Disorder of bone metabolism resulting in soft, malleable bones. Called rickets in children and osteomalacia in adults. Another name is “English disease”.
  • Symptoms : including muscle and bone pain, muscle cramps, knock-knees or bowlegs, waddling gait, deformation of ribs (“rachitic rosary”) and joints (“Marfan sign”)
  • Cause : mostly vitamin D deficiency, sometimes a disorder of vitamin D metabolism (eg as a result of liver disease or gene mutation); Vitamin D-independent causes (such as phosphate deficiency) are rare
  • Treatment : depending on the cause of rickets. Usually intake of vitamin D and calcium . If necessary, orthopedic aids against skeletal misalignments
  • Prevention : To prevent vitamin D deficiency, stay outdoors every day and eat a diet rich in vitamin D.

What is rickets?

Rickets (English disease, Rickets) or osteomalacia is a disorder of bone metabolism. In those affected, the incorporation of calcium and phosphate into the bone tissue is disturbed. If the disease occurs in children, doctors speak of rickets. In adults, however, this bone disease is called osteomalacia.

The most common cause of rickets is vitamin D deficiency. In other cases, a disturbed vitamin D metabolism is the reason for the disease, for example as a result of liver cirrhosis or – rarely – a gene mutation. Vitamin D-independent forms of the disease, such as rickets due to phosphate deficiency, are also rare.

Rickets: symptoms

Most often, the first signs of rickets appear in babies in the second to third month of life. These include:

  • restlessness
  • jumpiness
  • Sweating (especially) at the back of the head
  • Occipital baldness

In the third to fourth month of life, further rickets symptoms appear:

  • Muscle weakness (hypotension)
  • sagging abdominal wall
  • constipation
  • touch sensitivity
  • possibly signs of neuromuscular hyperexcitability (tetany), eg seizure-like muscle cramps, abnormal sensations
  • possibly epileptic seizures

In rickets, however, the focus is on skeletal changes :

  • abnormally soft, elastic skull bones (craniotabes)
  • Flattening of the occiput and protrusion of the forehead and crown of the head (caput quadratum = “square skull”)
  • O-legs or knock-knees
  • Bowing of the femoral neck (coxa vara), resulting in the “waddle” gait
  • Palpable and later also visible swelling of the cartilage-bone borders on the ribs (“rickets rosary”) and on joints (“Marfan sign”)
  • other bone deformities, eg kyphosis (backward curvature of the spine ), bell thorax (bell-shaped chest)

Significant changes in the ribs or chest can result in restricted lung function and bronchial diseases.

Another symptom of rickets is the delayed closure of the bone gaps in the skull (fontanelles).

In addition, rickets is often noticeable in the teeth : themilk teeth break through late. Caries and tooth enamel defects occur frequently.

In the case of the most common cause of rickets – vitamin D deficiency – symptoms such as muscle and joint pain , muscle weakness, seizure-like muscle cramps and paraesthesia occur. You can read more about this in the article Vitamin D deficiency .

Osteomalacia: symptoms

The clinical picture in adults – osteomalacia – manifests itself mainly through uncharacteristic bone pain and muscle weakness with the resulting gait disorders (waddle gait). In more severe cases, there is also softening and deformation of the bones, especially in the area of ​​​​the chest , hips and knees (eg bowlegs).

Osteomalacia is often accompanied by bone loss ( osteoporosis ), especially in older people.

Rickets: causes and risk factors

Vitamin D deficiency

The most common cause of rickets is vitamin D deficiency. This is mainly caused by the fact that the skin is not exposed to enough sunlight. The body can cover around 80 percent of its vitamin D requirements through its own production: the effective vitamin is produced in the skin from precursors under the influence of UV radiation.

The body absorbs the remaining 20 percent of the required amount of vitamin D through food.

There are essentially the following risk factors for vitamin D deficiency and thus also for vitamin D deficiency rickets:

  • insufficient exposure to the sun (eg, those who have been bedridden for a long time, residents of nursing homes, people who wear religious habit or chador, people with dark skin color who live in an area with little sun exposure)
  • Malnutrition or malnutrition
  • Impaired absorption or utilization of vitamin D (e.g. in chronic inflammatory bowel diseases, celiac disease or gastrointestinal operations)

Disorder of vitamin D metabolism

Disorders in vitamin D metabolism are other possible causes of rickets. For example, they can be caused by liver or kidney disease (such as liver cirrhosis, chronic kidney failure ).

Disorders in vitamin D metabolism are rarely hereditary. There are two forms of hereditary rickets:

  • Vitamin D-dependent rickets type 1 (VDAR I) : A gene mutation affects the activity of an enzyme that converts inactive vitamin D into its active form.
  • Vitamin D-dependent rickets type 2 (VDAR II) : The effect of the vitamin is impaired by mutations in the gene for the docking site of the vitamin (vitamin D receptor).

Vitamin D-independent causes

Also rare are forms of rickets that have developed independently of vitamin D. One of them is the so-called hypophosphatemic rickets (also called vitamin D-resistant rickets). It is usually based on a congenital genetic defect, which is why one also speaks of hereditary (hereditary) hypophosphatemic rickets. The genetic defect causes too much phosphate to be excreted through the kidneys. The result is a phosphate deficiency, which damages the bones – the body depends on sufficient phosphate to build them up.

Rarely does hypophosphatemic rickets – or in adults hypophosphatemic osteomalacia – develop in connection with a tumor disease. This can be, for example, a so-called giant cell tumor of the bones, but also prostate cancer or breast cancer . One then speaks of tumor-induced rickets or osteomalacia.

Rickets: examination and diagnosis

If you suspect your child has rickets, you should consult a pediatrician. Adults should first contact their family doctor if they have any signs of osteomalacia. He can classify the symptoms and, if necessary, refer the patient to a specialist.

anamnese

The first step towards diagnosis is a detailed conversation to collect the medical history ( anamnesis ). For example, the doctor asks the following questions:

  • Do you/your child spend a lot of time outdoors?
  • Do you or does your child eat a vegetarian or vegan diet?
  • Do you or does your child take any dietary supplements?
  • Is there bone pain?
  • Have changes in the skeleton become noticeable?

A thorough medical history can already lead to the suspicion of rickets or osteomalacia. However, further investigations are necessary for a reliable diagnosis.

Physical examination

The next step is the physical exam. The doctor examines the patient’s posture, gait and bones in particular. In children, palpation of the fontanelles (bone gaps in the child’s skull) can provide another indication of rickets: In rickets, a delayed closure of the fontanelles is observed (the gaps in the skull ossify later than normal).

laboratory values

Various laboratory values ​​are very important in the clarification of rickets or osteomalacia. The following blood values ​​​​are particularly important:

  • phosphates
  • calcium
  • alkaline phosphatase (AP)
  • Parathyroid hormone (PTH): a hormone produced by the thyroid gland
  • Calcidiol: storage form of vitamin D in the body; chemical formula: 25-OHD
  • calcitriol : activated form of vitamin D; chemical formula: 1,25-(OH)2D

The level of the various blood values ​​​​and their relationship to each other indicates the cause of rickets / osteomalacia. This is important because the different forms of rickets sometimes have to be treated differently.

For example, the combination of a normal phosphate level and increased values ​​for AP and PTH is found both in vitamin D deficiency rickets and in the hereditary forms of rickets VDAR I and VDAR II. In the last two, however, the calcidiol level is normal , while it is decreased in vitamin D deficiency rickets.

In order to distinguish between VDAR I and VDAR II, the doctor looks at the calcitriol level: it is low in VDAR I, but elevated in VDAR II.

roentgen

Doctors may also take x-rays to confirm the diagnosis. Bone changes characteristic of rickets can be seen on it. The images also allow an assessment of bone density.

Further investigations

In individual cases, other investigations may be useful. For example, in ambiguous cases of osteomalacia, a bone biopsy is sometimes done, which means that some bone tissue is removed and analyzed in a laboratory.

If the doctor suspects a tumor to be the cause of osteomalacia (tumour-induced osteomalacia), magnetic resonance imaging (magnetic resonance imaging, MRI) may be necessary to detect the tumor.

Rickets: treatment

The treatment of rickets or osteomalacia depends primarily on the cause of the disease and the age of the patient.

Treatment of vitamin D deficiency rickets

If a vitamin D deficiency is the cause of rickets, it is important to compensate for this with medication. The children receive vitamin D and additional calcium, whereby the dosage depends on the age at which the diagnosis is made (IU = “international unit”, international unit):

  • 1st year of life: 2000 IU of vitamin D3 and 40 to 80 mg of calcium per kilogram of body weight and day for 12 weeks. Thereafter, up to the end of the first year of life, 500 IU of vitamin D3 daily as prophylaxis.
  • 1 to 12 years: 3000 to 6000 IU of vitamin D3 and at least 500 mg of calcium per day for 12 weeks.
  • 12 years and older: 6000 IU vitamin D3 and 500 to 1000 mg calcium per day for 12 weeks.

A blood test is recommended three to four weeks after the start of therapy in order to adjust the dosage of vitamin D or calcium if necessary.

Risk groups should generally take 500 IU of vitamin D per day. This includes exclusively breastfed infants, the chronically ill, children/adolescents taking medication for epilepsy , and black-skinned migrants.

Further measures

If cramps or abnormal sensations, such as tingling or numbness, occur because of low calcium levels , calcium is given as an IV . As soon as the patient’s condition improves, the trace element should be administered orally (eg as an effervescent tablet) as soon as possible – if the calcium level is still too low.

When taking high doses of vitamin D, it is essential that you also take sufficient calcium. Otherwise, there is initially a risk of a seizure occurring as a result of a sharp drop in calcium levels.

If the soft bones lead to malpositions such as knock knees or bowlegs or scoliosis , orthopedic aids may be necessary. These include, for example, shoe inserts that compensate for an axial misalignment, or a corset for upright posture. Discuss the right treatment with the treating pediatrician or an orthopaedist.

Treatment of other forms of rickets

Patients with hypophosphatemic rickets or osteomalacia must take phosphate and active vitamin D (calcitriol). However, if the bone softening and deformation can be traced back to a tumor disease, it is sometimes sufficient to remove the tumor. However, if the condition of the bones does not improve afterwards, treatment with phosphorus and calcitriol becomes necessary.

The treatment of hereditary rickets form VDAR I consists of lifelong, daily intake of calcitriol or alpha-calcidiol. Calcium is also given during the first months of therapy.

Patients with VDAR II receive high doses of calcitriol and additional calcium. If this treatment is unsuccessful, high doses of calcium can be tried.

Rickets: course and prognosis

If the most common form of rickets – vitamin D deficiency rickets – is recognized and treated, the laboratory values ​​​​normalize after a few weeks. The skeletal changes that can be seen on the X-rays recede after weeks or months. Malpositions of the leg axes (eg bowlegs), which are often observed in rickets patients, do not usually require an operation ( osteotomy ), but usually straighten themselves out on their own. However, this may take two to three years.

prevent rickets

To prevent rickets or osteomalacia, the most important thing is to prevent the most common cause – vitamin D deficiency. You should also make sure that you get enough daylight for vitamin D synthesis in the skin. How much “sufficient” means depends, among other things, on your own skin type, the time of year and the geographical degree of latitude. You can find more detailed recommendations on this in the article Vitamin D deficiency .

Diet also makes a small contribution to vitamin D supply. Larger amounts of the vitamin are found in fish, liver and dairy products, for example. You can read more about this in the article Vitamin D foods high in content .

Vitamin D prophylaxis

In some cases, sun exposure and diet are insufficient to meet vitamin D needs. Then it can make sense to take vitamin D as a supplement (eg in the form of tablets or drops).

Such vitamin D prophylaxis should only be carried out in consultation with a doctor. He can use a blood test to find out whether and in what dosage you should take a vitamin D preparation. Be sure to stick to the recommended dose to avoid overdosing. Anyone who takes too much vitamin D out of concern about vitamin D deficiency and its consequences (such as rickets or osteomalacia) can develop kidney stones or kidney calcification, for example.

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