Conjunctivitis Allergy or Infection?

Conjunctivitis AllergyRed, itchy and watery eyes are the most common symptoms of an allergic reaction. Allergies are a growing menace in the United States. More than half the population in the United States tested positive for one or more allergen.


is a condition characterized by an inflammation of the conjunctiva (the inner surface of the eyelids and the outer surface of the eye). It is also known as Pink Eye or Madras Eye. This condition can be caused either by an infection or by an allergic reaction. The infection could be caused by an impending virus or bacteria.

It is important to distinguish between the two types of the said condition as the treatment for the two differs in nature.

What is Conjunctivitis Allergy?

The conjunctiva is a thin membrane covering the eye. When an allergen like pollen, dust mite or pet dander reaches this thin outer layer of the eye and irritates it, a whole lot of symptoms appear in the eye. The symptoms are mainly redness (dilation or inflammation of the small peripheral blood vessels in the eye), itching, swelling of eyelids, tearing, watery discharge, sensitivity to light source, pain and the sensation of a foreign body being lodged in the eye. The symptoms worsen with warm and dry weather. Rains and cooler temperatures improve the symptoms.

The most common irritants which cause ocular allergies are as follows:

  • Pollen
  • Dust mites
  • Animal skin, fur or secretions like saliva
  • Medications and Drugs
  • Cosmetics
  • Pollution
  • Smoke
  • Eye Drops

Types of Conjunctivitis Allergy Disorders

Allergic Conjunctival Disorders are of two types, namely,

Seasonal and Perennial

Both of them are IgE mediated and are acute allergic eye conditions. Seasonal is temporary and is limited to the particular season when the concentration of the irritant is high in the air. Perennial is when the symptoms are present all through the year. Seasonal Allergic Conjunctivitis is the most common form of ocular allergy.

Why does one get a pink eye in allergies?

This is a common symptom in hay fever or allergic rhinitis. Allergies are basically an auto immune response of the body. The immune system is hypersensitive. It starts to perceive otherwise harmless proteins in certain environmental elements as a possible threat. The immune system responds by producing antibodies, namely, Immunoglobin E (IgE). These antibodies react and bind with the protein causing the mast cells in the gut, pharynx and located subcutaneously under the skin to release a chemical, namely, histamine. Histamine causes the adverse reactions in the eye as discussed above.

Infectious Conjunctivitis

How is infectious pink eye caused?

Infectious pink eye is caused by bacterial or viral infection.
A viral infection of the upper respiratory tract or a common cold can bring about this condition. Itchy eyes with redness and a watery discharge are common symptoms.
Bacterial pink eye is caused by bacteria like Chlamydia trachomatis or Moraxella. It is characterized by a stringy, opaque yellowish discharge which causes the eye lids to stick together in the morning. Crusting of the infected eye and the surrounding areas are also common.
Infectious pink eye is extremely contagious and can spread very easily. Coming in touch with the infected person and his /her belongings may be enough to contract the disease.
The treatment for the infectious variant of the disease is usually done with antibiotic eye drops. The viral eye infection generally resolves on its own.

Treatment of Conjunctivitis Allergy

  • Once the irritant is identified it should be avoided as much as possible.
  • Antihistamine eye drops can negate the effects of the excess histamine and reduce the itching, burning and inflammation.
  • Medications which act as mast cell stabilizers are also used to bring the situation under control. Eye drops such as Lodoxamide and Nedocromil are mast cell stabilizers. They are given preference due to them having very few side effects. The only flaw is that they have a delayed response to the symptom.
  • Non Steroidal Anti Inflammatory Drugs (NSAIDs) are safe and extremely effective in eliminating the symptoms.
  • Corticosteroids can be used limitedly in extreme situations. Physicians reserve corticosteroids as the last option as they come with a bunch of side effects.
  • A combination eye drop like Patanol is often prescribed by physicians to combine the benefits of an antihistamine and a mast cell stabilizer. Until the latter kicks in, the antihistamine helps in controlling the symptoms.


  • Avoid the eye allergen by wearing wrap around glasses while going outside.
  • Keep doors and windows closed to keep away the air borne allergens.
  • Cold compress can bring relief from symptoms of red, itchy and watery eyes.
  • Install a HEPA enabled air filter to keep away the indoor allergens.
  • Using an air conditioner during summer months can help to minimize symptoms.
  • Proper hygiene regarding eye care needs to be maintained. This is especially true if one wear contact lenses.

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