A work up on Fluorosis

How many of us have seen patients presenting with tingling sensation in the limbs, low back ache or stiffness in the spine as in restriction of movements?
We at Kamineni institute of medical sciences, in Narketpally area of Nalgonda Dist. see many patients, usually those above 40 years of age, males and females alike, presenting to the OPD with the above symptoms. We seldom find the root cause and ultimately the patient receives symptomatic treatment.
We also see people, not just patients, walking with sticks at an early age who also lose normal sensations in their limbs. Our Professor of internal medicine requested to examine these patients and found prominent neurological findings suggestive of spinal cord involvement at various levels.

The endemic of fluorosis in Nalgonda district of Telangana has been long identified but fluorosis in patients is rarely identified.


So our professor inspired us to do a little work up on fluorosis to enrich our knowledge and throw light on some new interventions in tackling this endemic.

What should drive us to suspect fluorosis in a person?

The reason why fluorosis is not an easy diagnosis is perhaps because of its vague clinical presentation and an extensive overlap of clinical features with its differentials.
Having said that, it is appropriate to mention here the types of fluorosis viz.,

• Skeletal fluorosis 
• Dental fluorosis 

Dental fluorosis is relatively an easier diagnosis because of its specific dental changes which are mentioned below.
Dean's Index was published to classify dental fluorosis. It ranges from grade 1 (Aberrations in normal translucency of enamel) to Grade 5 (Brown staining of teeth with confluent pitting) [Dean's index]


The early warning signs of fluorosis are nausea, loss of appetite, gas formation, chronic diarrhoea or chronic constipation, peculiar changes in the teeth and allergic manifestations.
Early manifestations of skeletal fluorosis include parasthesia, discomfort in the back which may be dismissed as functional symptoms when in fact, they can be indicators of developing skeletal fluorosis. These symptoms progress to pain and stiffness in the back.
Neurological manifestations occur mostly due to compression of spinal cord due to spinal abnormalities developing as a result of fluorosis.

Fluorides affect the gastric mucosa causing variety of GIT abnormalities mentioned above.
Fluorosis can cause secondary hyperparathyroidism as fluoride binds to calcium causing the ionic calcium to decrease. This causes number of diseases like osteoporosis, hypertension, arteriosclerosis, neurological disease, etc.

Anemia is another frequent manifestation. Fluoride can bind to the calcium in the RBC membrane and makes the cell membrane more pliable. The RBCs develop pseudopodia like folds giving the cells a characteristic shape. These cells are called Echinocytes.

Clinical diagnostic criteria:
The following criteria should be met to diagnose fluorosis in a person

1. Residence in endemic area for > 10 years
2. Mottled tooth enamel
3. Urine fluoride level > 10 mg/L
4. Typical symptoms and findings on physical examination.
5. No evidence of other metabolic bone disorders found on review of medical history.

Here, it is important to mention certain additional manifestations of fluorosis

• Pineal gland is a target for fluoride accumulation. This can cause reduced melatonin production and altered sleep-wake cycle.
• Cardiovascular system is affected due to oxidative stress that promotes inflammatory mechanisms.
• There is a risk of impaired development of intelligence when growing children are exposed to high quantities of fluorides.
• The spine abnormalities can not only cause neurological symptoms but also can cause restriction of chest wall expansion. This effect can lead to restrictive lung disease.   

An interesting case presented to us a month back.
A 60 years old female patient presented to the emergency with shortness of breath and generalized edema for a few days. The patient has severe deforming spondyloarthropathy.
 Her 2D Echo showed pericardial effusion and RV dyskinesia. It also showed positive Kussmaul's sign ( lack of reducibility of IVC with respiration).

The above clip shows RV dyskinesia (sorry for the poor quality).

Kussmaul's sign in the above clip.


X-rays of her spine suggested a picture of ankylosing spondylosis. Fluorosis is one of the close differentials for AS but unfortunately, no attempt was made to diagnose fluorosis.

Diagnostic methods

Investigations should be tailored to the patient's complaints and needs.
Following investigations are useful depending upon the signs and symptoms of patient.

• Hemoglobin may be reduced
• Renal parameters may be altered.
• Nerve conduction studies.

Specific diagnostics include

• 24 hr urinary fluorides. In skeletal fluorosis, the value is usually greater than 10 mg/L. Normal urinary fluoride excretion is less than 1.5 mg/L. A person stricken with skeletal fluorosis excretes high level of fluorides for about 10 years.
•  Serum fluoride levels. Not routinely done. Normal fluoride level ranges from 0.002 - 0.008 mg/dL. In skeletal fluorosis, the value may go up to 0.02 - 0.19.
• The definitive diagnostic test would be Bone fluoride estimation from bone biopsy.
• Radiological studies
• Sand - like or granular pattern of the bone is the earliest radiological change observed on an X-ray.
• Increased bone density (Osteosclerosis), Osteoporosis
• Ossification of attachments of tendons, ligaments and muscles. Main feature in this regard would be ossification of Interosseous membrane in the forearm. There can also be ossification of posterior longitudinal ligament of the spine.
• There can be thickened tables of the skull bone
• Trabecular thickening followed by trabecular fusion which appear as focal round densities in the medullary bone.

SA/GAG test:
         A recent diagnostic test has come into picture to differentiate fluorosis from other skeletal abnormalities. It is SA/GAG test [Ratio of Sialic acid(SA) and Glycosaminoglycans(GAG)].
The sensitivity and specificity is yet to be determined. SA and GAGs are important components of bone matrix and disorders of bone would alter the levels of these components in the bone as well as in the serum. The SA/GAG normal individuals is 3-4. The ratio is reduced by 30% in Osteofluorosis.

• Water fluoride levels: Maximum permissible fluoride levels in the drinking water is 1.5 ppm. Concentrations above 1.5 ppm can cause dental fluorosis and much higher concentrations can cause skeletal fluorosis.  

POSSIBLE TREATMENT OPTIONS

Skeletal fluorosis has no established treatment just yet.
It is usually treated symptomatically and most importantly, by restriction of fluoride in drinking water!

It has been shown that at early stages of skeletal fluorosis, restriction of fluoride concentrated water can gradually reverse the symptoms by slowly excreting the accumulated fluoride in the bone.
Corrective surgeries for severe cases can be undertaken.

Methionine and vitamin E may have an effect by reducing fluoride accumulation in soft tissues.

Effect of Tamarind?
The National Institute of Nutrition (NIN) has found that consumption of 10 grams of boiled tamarind can enhance the excretion of fluorides from the body.
The mechanisms involved are not completely understood.
A study was conducted in 20 boys who consumed equal amounts of tamarind for about 18 days. The excretion of fluoride increased significantly compared to the control diet.


REFERENCES:

1. https://googleweblight.com/i?u=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4800930/&grqid=8zdpNS1t&hl=en-IN
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2940190/#!po=57.5000
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1003612/
4. https://www.jscimedcentral.com/Orthopedics/orthopedics-4-1069.pdf
5. https://www.ncbi.nlm.nih.gov/pubmed/11840184

Above is a small percentage of  what there is to learn and know about fluorosis. 
Any suggestions, comments, queries and additions are highly appreciated. The above content will be updated as soon as something new comes to our knowledge about fluorosis.