Fever and Allergy: Meaning, Causes, and Types of Allergic Reactions

Fever and Allergy: When it comes to your body temperature, how high is too much? A fever is defined as a temperature of 100.4 degrees Fahrenheit or above. When did you last have a fever? When tested orally, most persons have a body temperature of around 37°C (98.6°F) (a thermometer is placed under the tongue).

In the morning, the temperature might be as low as 36.3°C (97.4°F) and as high as 37.6°C (99.6°F) in the late afternoon. However, our body temperature rises in some circumstances, resulting in a fever. Allergies are our body’s reaction to substances it perceives as  dangerous “invaders.” In this article, we will discuss fever and allergy, the meaning, causes, types, and mechanisms of allergic reactions.

Fever

A fever is a rise in body temperature that occurs temporarily as a result of a disease. It is a sign that our body’s cells are battling and eradicating a variety of pathogens.

Fever refers to a higher-than-normal blood temperature that can affect both children and adults. A fever in an adult can be uncomfortable, but it is rarely dangerous unless it reaches 103° F (39.4° C) or higher.

Fever Causes

Fever can be caused by a number of different illnesses. Infections are the most common cause of a rise in body temperature. Pathogens can cause a variety of illnesses, including the common cold, pneumonia, TB, and others. The causes of fever are as follows:
1. Infections
2. Overexposure to sunlight
3. Dehydration
4. Silicosis
5. Withdrawal of Alcohol
6. Gastroenteritis
7. Heat exhaustion

Symptoms of Fever

The most common symptoms of fever include:
1. Chills
2. Paleness
3. Vomiting and Diarrhoea
4. Dehydration
5. Muscle Aches
6. Sore eyes
7. Confusions and Headache
8. Fatigue and seizures
9. Difficulty in swallowing
10. Greater irritability

Fig: Symptoms of Fever

These were some of the most typical fever symptoms. Other symptoms vary depending on the aetiology, duration of the fever, and body temperature fluctuations.

Treatment of Fever

Fever can be treated in a variety of ways, which are mainly determined by the symptoms.
Suppose the fever is light, less than 101 degrees, or is caused by pathogens. In that case, the doctor may prescribe medications such as paracetamol and antibiotics, as well as a healthy diet to avoid dehydration.
1. Drugs like aspirin and ibuprofen can be used to treat fever.
2. If the patient’s fever is caused by a bacterial illness, an antibiotic may be prescribed.
3. Non-steroidal anti-inflammatory medicines (NSAIDs) can be used to treat viral infections.

Allergy

Allergy is a condition in which the immune system reacts in a way that is harmful to the person.

Allergy Causative Agents or Allergens

Fig: Causative Agents of Allergies

Allergens are proteins or glycoproteins (although nucleic acids and polysaccharides can also be allergens) that cause the immune system to produce IgE antibodies. Pollen, mold, animal dander, latex, certain foods, dust, cosmetics, drugs, and insect stings are examples of generally harmless substances that can cause allergies.

Allergy Symptoms

Fig: Allergy Symptoms

1. A blocked or congested nose
2. A runny nose
3. Wheezing and coughing
4. Red, itchy, watery eyes
5. Swelling of the lips, face & throat
6. Stomach Cramps
7. Nausea & vomiting
8. A Swollen Tongue
9. Shortness of breath
10. Sore Throat
11. A red itchy rash
12. Diarrhoea
13. Difficulty breathing
14. Headache
15. Dizziness and fainting
16. Fever, Fatigue
17. Changes in heart rate and low blood pressure

Types of Allergic (Hypersensitivity) Reactions

Different classifications exist for allergic or hypersensitivity reactions. It could be humoral or cellular in nature. It’s considered an immediate reaction if symptoms appear within minutes of antigen exposure, a late reaction if symptoms appear after hours, and a delayed reaction if symptoms appear after days.

Based on the different immunological mechanisms P.G.H.Gell and R.R.A.Coomb (1963) categorized the hypersensitivity reactions into four principal groups viz. Type I – IV, of which Type I, II, and III are caused by antibodies and Type IV is caused by lymphocytes.

Fig: Types of Allergic Reactions- Type I, Type II, Type III, Type IV

Mechanism of Allergic (Type I) Reactions

1. Pollen grains produce hypersensitivity because they come into contact with the upper respiratory tract, nostrils, oral cavity (mouth), and eyes.
2. Pollen produces proteins that cause hay fever or rhinitis when it comes into close contact with a moist eye surface.
3. Pollen produces proteins that cause hay fever or rhinitis when it comes into close contact with a moist eye surface.
4. By producing a high degree of turbulence in the airflow that is deposited in the trachea and upper bronchi, the nasal cavity filters them out.
5. The majority of pollen grains are swallowed and build up in the stomach. Pollen releases proteins when it passes through the stomach, and a small amount of these proteins enters the bloodstream, triggering hypersensitivity reactions.
6. Antibodies are formed in allergic persons’ lymphoid tissues by distinct antibody-forming cells in response to their first exposure to allergens (proteins) derived from pollen grains.
7. These IgE antibodies circulate in the bloodstream and get attached to the surface of mast cells or basophilic granulocytes.

Fig: Mast cell degranulation

8. Mast cells can be present in the lungs, upper respiratory tract membranes, skin, and gastrointestinal system in humans. Mast cells are densely packed with granules containing histamine and a variety of other biologically active chemicals such as bradykinin, prostaglandins, and others.
9. The specific allergens (from a similar type of pollen) bind to pairs of adjacent IgE molecules on the mast cell surface when they have encountered again (second exposure).
10. The rapid release of tissue mediators, primarily histamine, from granules released by mast cells is triggered by this binding.
11. Histamine causes wheal and raised spots on the skin, as well as itching and redness.
12. Symptoms can also manifest themselves in the nose and eyes like sneezing, blocked nose, cold plus reddened, swollen, and itching eyes.

Common Allergic Reactions

Allergic diseases can affect any area of the body, but the nose, eye, and chest are the most commonly affected, resulting in hay fever, rhinitis, or asthma symptoms. Allergies usually manifest themselves in the skin and eyes. The following are some of the most prevalent pollen allergies.

1. Hay fever

Fig: Hay Fever Symptoms

A. This allergy is a seasonal type.  This form of allergy is caused by pollen grains from specific grasses, weeds, and trees, while mold spores can also induce symptoms.
B. Attacks may occur seasonally in spring, summer, winter, or rainy season, depending on where the patients live and the pollination period of a particular plant.
C. It’s possible to experience a variety of symptoms. The lining of the nose swells, and a runny discharge emerges.
D. Sneezing fits and itching of the throat and palate are common, and the eyes may be affected as well.
E. Dr. Blackley, a British scientist, was the first to prove that pollen grains are the cause of hay fever in 1873.

2. Rhinitis

Fig: Allergic Rhinitis

A. It’s a form of allergy that lasts for a perennial time.
B. The symptoms are similar to those of hay fever, except they occur all year. The lining of the nose swells, and a runny discharge emerges. Sneezing fits and itching of the throat and palate are common, and the eyes may be affected as well.
C. Non-seasonal allergens, such as pollen grains from grasses and other plants that bloom all year, trigger the disorder. Rhinitis can also be caused by particular mould spores and elements found in house dust.

3. Conjunctivitis

Fig: Conjunctivitis

As adults, people are more likely to develop an allergic condition of the eyes. Allergic rhinitis is frequently related to allergic conjunctivitis. Itching of the eyes, which causes regular rubbing, burning sensation, and watery eyes, are a common problem.

4. Asthma

A. Asthma can be caused by allergic or non-allergic triggers.
B. Environmental allergens such as pollen grains and spores produce allergic asthma when inhaled.
C. Because of the inflamed mucous membrane and the formation of phlegm inside the mucous membrane, the patients may experience attacks that block the flow of air to the lungs.
D. Breathing becomes difficult, necessitating forced breathing. The rush of air through the restricted airways causes a wheezing sound.
E. An unpleasant cough may emerge at the same time. Asthma can strike at any age, and if left untreated, it can develop into a chronic condition.

Summary

A fever is a rise in body temperature that occurs temporarily as a result of a disease. It is a sign that our body’s cells are battling and eradicating a variety of pathogens. Infections such as colds and stomach bugs(gastroenteritis) are the most common causes of fever. Infections of the ear, lung, skin, throat, bladder, or kidney are among the other causes. Fever can be treated in a variety of ways, which are mainly determined by the symptoms. Suppose the fever is light, less than 101 degrees, or is caused by pathogens. In that case, the doctor may prescribe medications such as paracetamol and antibiotics, as well as a healthy diet to avoid dehydration.

An Allergy is a condition in which the immune system reacts in a way that is harmful to the person. Allergens are proteins or glycoproteins (although nucleic acids and polysaccharides can also be allergens) that cause the immune system to produce IgE antibodies. Allergists recognize four types of allergic reactions: Type I or anaphylactic reactions, type II or cytotoxic reactions, type III or immunocomplex reactions, and type IV or cell-mediated reactions. The allergic reaction causes diseases that include hay fever, food allergies, rhinitis,  allergic asthma, and anaphylaxis.

Frequently Asked Questions (FAQs) on Fever and Allergy

Q.1. What is an allergy?
Ans: An allergy is a condition in which the immune system reacts in a way that is harmful to the person. Allergens are proteins or glycoproteins (although nucleic acids and polysaccharides can also be allergens) that cause the immune system to produce IgE antibodies.

Q.2. What is a fever?
Ans: A fever is a rise in body temperature that occurs temporarily as a result of a disease. It is a sign that our body’s cells are battling and eradicating a variety of pathogens.

Q.3. What causes fever?
Ans: Infections such as colds and stomach bugs(gastroenteritis) are the most common causes of fever. Infections of the ear, lung, skin, throat, bladder, or kidney are among the other causes.

Q.4. What are the diseases caused by allergic reactions?
Ans: The allergic reaction causes diseases that include hay fever, food allergies, rhinitis,  allergic asthma, and anaphylaxis.

Q.5. What are the 4 types of allergies?
Ans: Allergists recognize four types of allergic reactions: Type I or anaphylactic reactions, type II or cytotoxic reactions, type III or immunocomplex reactions, and type IV or cell-mediated reactions.

Learn About Allergens Here

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