Allergy

Allergy facts

• Allergy involves an exaggerated response of the immune system.
• The immune system is the body's organized defense mechanism against foreign invaders,
• particularly infections.
• Allergens are substances that are foreign to the body and can cause an allergic reaction.
• IgE is the allergy antibody.
• Allergies can develop at any age.
• Your risk of developing allergies is related to your parents' allergy history.

Who is at risk and why?

Allergies can develop at any age, possibly even in the womb. They commonly occur in children but may give rise to symptoms for the first time in adulthood. Asthma may persist in adults while nasal allergies tend to decline in old age.
Why, you may ask, are some people "sensitive" to certain allergens while most are not? Why do allergic persons produce more IgE than those who are non-allergic? The major distinguishing factor appears to be heredity. For some time, it has been known that allergic conditions tend to cluster in families. Your own risk of developing allergies is related to your parents' allergy history. If neither parent is allergic, the chance that you will have allergies is about 15%. If one parent is allergic, your risk increases to 30% and if both are allergic, your risk is greater than 60%.
Although you may inherit the tendency to develop allergies, you may never actually have symptoms. You also do not necessarily inherit the same allergies or the same diseases as your parents. It is unclear what determines which substances will trigger a reaction in an allergic person. Additionally, which diseases might develop or how severe the symptoms might be is unknown.
Another major piece of the allergy puzzle is the environment. It is clear that you must have a genetic tendency and be exposed to an allergen in order to develop an allergy. Additionally, the more intense and repetitive the exposure to an allergen and the earlier in life it occurs, the more likely it is that an allergy will develop.
There are other important influences that may conspire to cause allergic conditions. Some of these includesmoking, pollution, infection, and hormones.

What are common allergic conditions, and what are allergy symptoms and signs?

The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Although the various allergic diseases may appear different, they all result from an exaggerated immune response to foreign substances in sensitive people. The following brief descriptions will serve as an overview of common allergic disorders.

Allergic Eczema

Allergic eczema (atopic dermatitis) is an allergic rash that is usually not caused by skin contact with an allergen. This condition is commonly associated with allergic rhinitis or asthma and features the following symptoms:

• Itching, redness, and or dryness of the skin
• Rash on the face, especially children
• Rash around the eyes, in the elbow creases, and behind the knees, especially in older children and adults (rash can be on the trunk of the body)

Eczema is a skin condition caused by inflammation.Atopic dermatitis is the most common of the many types of eczema. While the word "dermatitis" means inflammation of the skin, "atopic" refers to an allergic tendency, which is often inherited. These eczema sufferers have a higher risk of developing other allergic conditions (like asthma or hay fever).
Eczema is a chronic problem for many people. It is most common among infants, many of whom outgrow it before school age.

Atopic Dermatitis - This condition is the most common of all pediatric dermatoses. For the majority of patients, the onset occurs during infancy. There are symmetrical patches of erythema, exudation, and scale involving the cheeks and chin. It is not unusual also to see widespread involvement of the trunk and extensor extremities during infancy; the diaper area is most often spared.

This figure shows erythema and fissuring on the weight-bearing surface of the foot. This disorder, which tends to be worse in the winter months, is called juvenile plantar dermatitis. It is much more common in children with atopic dermatitis. Juvenile plantar dermatitis, which has also been called wet-dry foot syndrome, is caused by excessive sweating of the feet in occlusive footwear and rapid drying in a low-humidity environment. The use of emollient ointments is extremely helpful.

Allergic contact dermatitis: 

A red, itchy, weepy reaction where the skin has come into contact with a substance that the immune system recognizes as foreign, such as poison ivy, poison oak or poison sumac or certain preservatives in creams and lotions. This type of reaction reflects a specific sensitivity or allergyto a specific substance. Also called allergic contacteczema.

Nickel contact dermatitis. The development of an itchy eczematous eruption near the umbilicus is virtuallypathognomonic for contact dermatitis to nickel. The source is the small metal snap in the blue jeans or the metal belt buckle. The simultaneous occurrence of an id reaction, sometimes with small lichenoid papuleson the elbows and knees, is very common. 

Lesions can be treated effectively with topical corticosteroids, but the only cure results from strict avoidance of nickel. This is easier said than done. Parents must buy jeans without snaps or sew in a small piece of fabric to protect the underlying skin. Families should be reminded that wearing jeans with a metal snap for just several hours out of the month would reactivate the entire process. Children with contact dermatitis to nickel should also avoid metal jewelry and should be advised against ear piercing.  

Indian scientists identify molecule to help cancer treatment

A team of Indian researchers, led by Dr Sathees C Raghavan of the Indian Institute of Science, Bangalore, have identified a molecule which they claim will revolutionise the cure for cancer. The molecule has been named after "Sathees as SCR7" and a detailed account of it has been carried in the international scientific journal "Cell." 

"The discovery could be a major step in improvement of the existing regimens for cancer treatment," Sathees, an Assistant Professor of IISc, told reporters here yesterday. "We hope that this discovery represents a milestone in development of new generation drugs to treat cancer," Sathees, who hails from Kannur district in Kerala, said. 

Scientists world over believe that the double-strand break (DSB) of DNA is one of the most lethal form of DNA damage, resulting in drastic consequences such as genome instability, and cancer. DSB is primarily repaired by two pathways, homogeneous recombination and non-homogeneous end joining, which was considered as a major route for the repair of DSBs in humans, he said. The inhibitor SCR7 targets non-homogeneous end joining and offers a strategy towards the treatment of cancer, he said.
"In our extensive scientific investigation carried out at IISc-Bangalore, we have successfully reported that SCR7 prolonged survival by either inducing tumour regression or inhibiting tumour growth in three out of the four tumour mice models tested", he said. When co-administered with the DSB-inducing treatment modalities such as radiation or chemotherapeutic agents, SCR7 could prove effective even on unresponsive tumours. The team that made the discovery included researchers from IBAB, Bangalore, KLE College of Pharmacy, Bangalore and ACTREC, Mumbai.

Human hands 'evolved for fighting'

Human hands may have built the Taj Mahal and adorned the ceiling of the Sistine Chapel with glorious art, but researchers have found they evolved – not just for manual dexterity - but primarily for fighting.
Compared with apes, humans have shorter palms and fingers and longer, stronger, flexible thumbs - features that have been long thought to have evolved so our ancestors could make and use tools, a new study has found.

For a University of Utah study, men whacked punching bags, suggesting human hands evolved not only for the manual dexterity needed to use tools, play a violin or paint a work of art, but so men could make fists and fight.
"The role aggression has played in our evolution has not been adequately appreciated," said University of Utah biology Professor David Carrier, senior author of the study.
"There are people who do not like this idea, but it is clear that compared with other mammals, great apes are a relatively aggressive group, with lots of fighting and violence, and that includes us," Carrier said.
"We are the poster children for violence". Humans have debated for centuries "about whether we are, by nature, aggressive animals," he added.
As our ancestors evolved, "an individual who could strike with a clenched fist could hit harder without injuring themselves, so they were better able to fight for mates and thus more likely to reproduce," he said.
Fights also were for food, water, land and shelter to support a family, and "over pride, reputation and for revenge," he added.
"If a fist posture does provide a performance advantage for punching, the proportions of our hands also may have evolved in response to selection for fighting ability, in addition to selection for dexterity," Carrier says.
Carrier and co-author Michael H Morgan conducted their study to identify any performance advantages a human fist may provide during fighting.
The first experiment involved 10 male students and non-students – ages 22 to 50 and all of them with boxing or martial arts experience – hit a punching bag as hard as they could.
Surprisingly, the peak force was the same, whether the bag was punched with a fist or slapped with an open hand.
"Because you have higher pressure when hitting with a fist, you are more likely to cause injury" to tissue, bones, teeth, eyes and the jaw, Carrier said.
The second and third experiments tested the hypothesis that a fist provides buttressing to protect the hand during punching.
"Because the experiments show the proportions of the human hand provide a performance advantage when striking with a fist, we suggest that the proportions of our hands resulted, in part, from selection to improve fighting performance," Carrier said.

Drugs Used in Dentistry

 

There are a number of different drugs your dentist may prescribe, depending on your condition. Some medications are prescribed to fight certain oral diseases, to prevent or treat infections, or to control pain and relieve anxiety.

Here you will find a description of the most commonly used drugs in dental care. The dose of the drugs and instructions on how to take them will differ from patient to patient, depending on what the drug is being used for, patient's age, weight, and other considerations.

Even though your dentist will provide information to you about any medication he or she may give to you, make sure you fully understand the reasons for taking a medication and inform your dentist of any health conditions you may have.

Drugs to Control Pain and Anxiety

Local anesthesia, general anesthesia, nitrous oxide, or intravenous sedation is commonly used in dental procedures to help control pain and anxiety. Other pain relievers include prescription or nonprescription anti-inflammatory drugs, acetaminophen (Tylenol), and anesthetics.

Anti-inflammatory drugs

Corticosteroids are anti-inflammatory drugs that are used to relieve the discomfort and redness of mouth and gum problems. Corticosteroids are available by prescription only and are available as pastes under such brand names as Kenalog in Orabase, Orabase-HCA, Oracort, and Oralone.

Your dentist may recommend a nonprescription anti-inflammatory drug -- such as Motrin -- to relieve mild pain and/or swelling caused by dental appliances, toothaches, and fevers. Tylenol may also be given.

Note: Unless directed by your dentist, never give infants and children aspirin.

Anesthetics

Dental anesthetics are used in the mouth to relieve pain or irritation caused by many conditions, including toothache, teething, and sores in or around the mouth (such as cold sores, canker sores, and fever blisters). Also, some of these medicines are used to relieve pain or irritation caused by dentures or other dental appliances, including braces.

Anesthetics are available either by prescription or over-the-counter and come in many dosage forms including aerosol spray, dental paste, gel, lozenges, ointments, and solutions. Dental anesthetics are contained in such brand name products as Ambesol, Chloraseptic, Orajel, and Xylocaine.

Note: The FDA has issued a warning to consumers about the use of benzocaine, the main ingredient in over-the-counter liquids and gels used to reduce teething pain in very young children. Benzocaine is associated with a rare but serious condition called methemoglobinemia, which greatly reduces the amount of oxygen carried through the bloodstream. The FDA says benzocaine products should not be given to children younger than age 2 unless under the supervision of a health care professional.

Also, because the elderly are particularly sensitive to the effects of many local anesthetics, they should not use more than directed by the package label or the dentist. Anesthetics used for toothache pain should not be used for a prolonged period of time; they are prescribed for temporary pain relief until the toothache can be treated. Denture wearers using anesthetics to relieve pain from a new denture should see their dentist to determine if an adjustment to the appliance is needed to prevent more soreness.

Drugs to Control Plaque and Gingivitis

Chlorhexidine is an antibiotic drug used to control plaque and gingivitis in the mouth or in periodontal pockets (the space between your gum and tooth). The medication is available as a mouth rinse and as a gelatin-filled chip that is placed in the deep gum pockets next to your teeth after root planing. The drug in the gelatin-filled chip is released slowly over about seven days. Dental products containing this antibacterial are marketed under various prescription-only brand names, such as Peridex, PerioChip, and PerioGard, as well as other over-the-counter trade names.

Note: Chlorhexidine may cause an increase in tartar on your teeth. It may also cause staining of the tooth, tooth filling, and dentures or other mouth appliances. Brushing with a tartar-control toothpaste and flossing your teeth daily may help reduce this tartar build-up and staining. In addition, you should visit your dentist at least every six months to have your teeth cleaned and your gums examined. Be sure to tell your dentist if you have ever had any unusual or allergic reaction to this medicine or to skin disinfectants containing chlorhexidine.

Antiseptics

Your dentist may recommend the use of an over-the-counter antiseptic mouth rinse product to reduce plaque and gingivitis and kill the germs that cause bad breath.

Drugs Used to Treat Periodontal Disease

The doxycycline periodontal system (marketed as Atridox) contains the antibiotic doxycycline and is used to help treat periodontal disease. Doxycycline works by preventing the growth of bacteria. Doxycycline periodontal system is placed by your dentist into deep gum pockets next to your teeth and dissolves naturally over seven days.

Note: Tell your dentist if you have ever had any unusual or allergic reaction to doxycycline or to other tetracyclines. Use of doxycycline periodontal system is not recommended during the last half of pregnancy or in infants and children up to 8 years of age because the product may cause permanent discoloration of teeth and slow down bone growth. Use of doxycycline periodontal system is not recommended, if breastfeeding, since doxycycline passes into breast milk. This class of drugs also may decrease the effectiveness of estrogen-containing birth control pills, increasing the chance of unwanted pregnancy.

Drugs Used to Prevent Tooth Decay

Fluoride is a drug used to prevent tooth decay. It is available on a nonprescription basis in many toothpastes. It is absorbed by teeth and helps strengthen teeth to resist acid and block the cavity-forming action of bacteria. As a varnish or a mouth rinse, fluoride helps reduce tooth sensitivity. Prescription-strength fluoride is available as a liquid, tablet, and chewable tablet to take by mouth. It usually is taken once daily. It is prescribed for children and adults whose homes have water that is not fluoridated (has not had fluoride added to water).

Note: Before taking fluoride, be sure to tell your dentist if you are allergic to fluoride, tartrazine (a yellow dye in some processed foods and drugs), or any other drugs. Do not take calcium, magnesium, or iron supplements while taking fluoride without checking with your dentist. Tell your dentist if you are on a low-sodium or sodium-free diet. Do not eat or drink dairy products one hour before or one hour after taking fluoride. Fluoride can cause staining of the teeth.

Dry Mouth Drugs

Pilocarpine, marketed as Salagan, may be prescribed by your dentist if you have been diagnosed with dry mouth. The drug stimulates saliva production.

Other Antibiotics

• Tetracyclines (the class of drugs including demeclocycline, doxycycline, minocycline, oxytetracycline, and tetracycline) and the drug triclosan (marketed as Irgasan DP300) are also used in dentistry. These medications may be used either in combination with surgery and other therapies, or alone, to reduce or temporarily eliminate bacteria associated with periodontal disease, to suppress the destruction of the tooth's attachment to the bone or to reduce the pain and irritation of canker sores. Dental antibiotics come in a variety of forms including gels, thread-like fibers, microspheres (tiny round particles), and mouth rinses.

• Muscle Relaxants may be prescribed to reduce your stress to help you stop grinding your teeth and to treat temporomandibular joint disorders.

• Antifungals are prescribed to treat oral thrush. The goal of treatment is to stop the spread of the Candida fungus. Antifungal medicines are available in tablets, lozenges, or liquids that are usually "swished" around in your mouth before being swallowed.