Showing posts with label Rickets. Show all posts
Showing posts with label Rickets. Show all posts

15.11.09

answer to the saudi medical council question examination

Rickets
Related concepts:
Vitamin D Deficient Rickets, The rachitic rosary
Introduction:
Good health is often a balancing act. Too much sun exposure can cause unwanted sunburn in babies, but too little sun exposure can lead to vitamin D deficient rickets.

Breast milk does not necessarily contain much vitamin D. Neither does cow?s milk, nor most baby foods. Theoretically, mothers and babies can produce their own when their skin is exposed to sunlight. However, the optimal amount of sunlight for each baby is different and difficult to determine. Exposure to direct sunlight in young babies also carries the potential increased risk for burns and eventual development of skin cancer.p>

What is it?
Babies who do not get enough or produce enough vitamin D can develop rickets, the failure of developing bones to form properly. In the absence of adequate amounts of vitamin D, the body steals calcium from the bones to keep the blood levels of calcium high enough for life.

Who gets it?
Breast-fed babies whose mothers do not get adequate time in the sun can develop rickets. This is especially true in colder climates and in darker-skinned individuals. Window panes, sunscreen, (and sometimes smog or haze) are able to block the sun?s rays needed to create vitamin D.

Today?s infant formulas are supplemented with plenty of vitamin D.

Low birth weight babies and kids with underlying conditions, such as celiac disease or cystic fibrosis, are more susceptible to rickets. Medications such as steroids and anti-seizure drugs can also increase the risk of rickets.

Several metabolic, liver, and kidney diseases can interrupt the normal functioning of the calcium/vitamin D system and lead to rickets.

What are the symptoms?
In rickets, the bones do not form properly. Often the first noticeable instance of this is the thin, pliable skull. Pressing on it can feel like pressing on a ping-pong ball. The head shape may be abnormal.

Teething may be delayed and the teeth may be poorly formed. Severe cavities are common.

The wrists and ankles may appear swollen. The tips of the rib bones can enlarge creating a string of lumps called the rachitic rosary. Bowed legs, knock-knees, or fractures are common.

Kids with rickets tend to sweat more than average.

Is it contagious?
No

How long does it last?
Rickets lasts until treated.

How is it diagnosed?
Rickets is suspected by the history and the physical examination. The diagnosis is confirmed by lab tests and x-rays.

How is it treated?
For children with nutritional rickets, giving vitamin D will begin reversing the problem. Other underlying problems may require additional treatment.

How can it be prevented?
Babies only need an average of 400 IU of vitamin D per day to prevent vitamin D deficient rickets. Because getting the right amount of sun exposure is unreliable and because of the potential risks of direct sunlight to young babies, the American Academy of Pediatrics does not recommend sun exposure as a strategy for preventing rickets. Instead, they recommend that all babies who are exclusively breastfed receive vitamin D supplementation. Babies who are taking less than 17 ounces of formula also need vitamin D supplements.

answer to the saudi medical council question examination

Rickets is a disorder caused by a lack of vitamin D, calcium, or phosphate. It leads to softening and weakening of the bones.

Causes
Vitamin D helps the body control calcium and phosphate levels. If the blood levels of these minerals become too low, the body may produce hormones that cause calcium and phosphate to be released from the bones. This leads to weak and soft bones.

Vitamin D is absorbed from food or produced by the skin when exposed to sunlight. Lack of vitamin D production by the skin may occur in people who:

Live in climates with little exposure to sunlight
Must stay indoors
Work indoors during the daylight hours
You may not get enough Vitamin D from your diet if you:

Are lactose intolerant (have trouble digesting milk products)
Do not drink milk products
Follow a vegetarian diet
Infants who are breastfed only may develop vitamin D deficiency. Human breast milk does not supply the proper amount of vitamin D. This can be a particular problem for darker-skinned children in winter months (when there are lower levels of sunlight).

Not getting enough calcium and phosphorous in your diet can also lead to rickets. Rickets caused by a lack of these minerals in diet is rare in developed countries, because calcium and phosphorous are found in milk and green vegetables.

Your genes may increase your risk of rickets. Hereditary rickets is a form of the disease that is passed down through families. It occurs when the kidneys are unable to hold onto the mineral phosphate. Rickets may also be caused by kidney disorders that involve renal tubular acidosis.

Disorders that reduce the digestion or absorption of fats will make it more difficult for vitamin D to be absorbed into the body.

Occasionally, rickets may occur in children who have disorders of the liver, or who cannot convert vitamin D to its active form.

Rickets is rare in the United States. It is most likely to occur in children during periods of rapid growth, when the body needs high levels of calcium and phosphate. Rickets may be seen in children ages 6 - 24 months. It is uncommon in newborns.

Symptoms
Bone pain or tenderness
Arms
Legs
Pelvis
Spine
Dental deformities
Delayed formation of teeth
Decreased muscle tone (loss of muscle strength)
Defects in the structure of teeth; holes in the enamel
Increased cavities in the teeth (dental caries)
Progressive weakness
Impaired growth
Increased bone fractures
Muscle cramps
Short stature (adults less than 5 feet tall)
Skeletal deformities
Asymmetrical or odd-shaped skull
Bowlegs
Bumps in the ribcage (rachitic rosary)
Breastbone pushed forward (pigeon chest)
Pelvic deformities
Spine deformities (spine curves abnormally, including scoliosis or kyphosis)
Exams and Tests
A physical exam reveals tenderness or pain in the bones, rather than in the joints or muscles.

The following tests may help diagnose rickets:

Arterial blood gases
Blood tests (serum calcium)
Bone biopsy (rarely done)
Bone x-rays
Serum alkaline phosphatase
Serum phosphorus
Other tests and procedures include the following:

ALP (alkaline phosphatase) isoenzyme
Calcium (ionized)
PTH
Urine calcium
Treatment
The goals of treatment are to relieve symptoms and correct the cause of the condition. The cause must be treated to prevent the disease from returning.

Replacing calcium, phosphorus, or vitamin D that is lacking will eliminate most symptoms of rickets. Dietary sources of vitamin D include fish, liver, and processed milk. Exposure to moderate amounts of sunlight is encouraged. If rickets is caused by a metabolic problem, a prescription for vitamin D supplements may be needed.

Positioning or bracing may be used to reduce or prevent deformities. Some skeletal deformities may require corrective surgery.

Outlook (Prognosis)
The disorder may be corrected by replacing vitamin D and minerals. Laboratory values and x-rays usually improve after about 1 week, although some cases may require large doses of minerals and vitamin D.

If rickets is not corrected while the child is still growing, skeletal deformities and short stature may be permanent. If it is corrected while the child is young, skeletal deformities often improve or disappear with time.

Possible Complications
Chronic skeletal pain
Skeletal deformities
Skeletal fractures, may occur without cause
When to Contact a Medical Professional
Call your child's health care provider if you notice symptoms of rickets.

Prevention
You can prevent rickets by making sure that your child gets enough calcium, phosphorus, and vitamin D in the diet. People who have gastrointestinal or other disorders may need to take supplements. Ask your child's health care provider.

Kidney (renal) causes of poor vitamin D absorption should be treated right away. People who have renal disorders should have their calcium and phosphorus levels monitored regularly.

Genetic counseling may help people who have a family history of inherited disorders that can cause rickets.

Alternative Names
Osteomalacia in children; Vitamin D deficiency; Renal rickets

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