Allergic shiners are caused by the pooling of blood under the eyes, due to the swelling of the tissue in the nasal cavities.
Allergic shiners are not usually considered a serious problem, although they can be unsightly. They can be treated and prevented by taking allergy medications and avoiding allergy triggers.
This article describes the symptoms and causes of allergic shiners and outlines the treatments available.
Differences to black eyes
An allergic shiner may resemble a black eye, with the skin under the eye usually purple or blue in color.
Although they may look similar, allergic shiners and black eyes are quite different.
In the case of allergic shiners, the blood has difficulty draining from the facial veins due to swelling in that area of the face and head.
Conversely, black eyes are due to trauma, and they involve bleeding under the skin caused by damaged capillaries or veins.
Allergic shiners are also usually accompanied by other symptoms of nasal allergies.
Other causes of dark circles under the eyes include:
- lack of sleep
- too much salt in the diet
- iron deficiency
- getting older and the skin thinning
Some people may also inherit genes from their parents that cause the skin under their eyes to appear darker.
Symptoms of allergic shiners include a blue or purple tint, resembling bruising, and what looks like dark shadows under the eyes.
Most people with allergic shiners will also have other allergy symptoms, such as:
- itchy throat
- runny nose
- congestion of sinuses and nose
- itchy, watery, or red eyes
Many people mistake the symptoms of allergies for the onset of a cold, flu, or sinus infection. However, allergy symptoms tend to persist for more than the 1 or 2 weeks these other conditions would normally linger. Colds and infections also tend to cause body aches and a fever, whereas allergy symptoms do not.
Depending on the time of the year and exposure to the allergen, the symptoms of an allergy may come and go or vary in severity.
Causes and risk factors
Hay fever, an allergy to plant pollen, may cause allergic shiners.
Allergic shiners are caused by congestion in the nasal passages and sinuses. This congestion restricts blood drainage from these areas, causing small veins below the eyes to get wider and pool with blood.
The swelling and excess blood is visible through the thin skin below the eyes and appears as dark circles.
Allergic rhinitis, also known as nasal allergy, is one of the most common causes of nasal congestion.
Allergic reactions occur when the body's immune system responds to a foreign body, such as pollen or pet dander. The immune system mistakenly treats these substances, which are known as allergens, as if they were harmful.
Common allergens, all of which can cause allergic shiners, include:
- dust mites
- pet dander
- mold and fungus
- cockroach feces
There are also many types of allergies to food, such as to dairy, eggs, nuts, or wheat.
Furthermore, some environmental irritants can make nasal congestion and other allergy symptoms worse, such as:
- air pollution
- perfumes and other fragrances
- tobacco smoke
People with allergic conjunctivitis, which causes allergy symptoms that affect the eyes, are more likely to experience allergic shiners than others. Symptoms of allergic conjunctivitis include swelling, watering, itching, and redness of the eyes.
Another risk factor for the development of allergic shiners is the time of year. People with seasonal allergies will probably notice that their symptoms are only present at a particular time of year, which may help them to pinpoint the allergen responsible.
If allergy symptoms are worse in early spring, it suggests an allergy to tree pollen. Symptoms that appear in late spring and summer indicate a grass pollen allergy, while allergies during fall may be caused by a reaction to ragweed.
Indoor allergies, on the other hand, can occur year-round but may be worse in winter when there is less airflow through a home. Common indoor allergens include pet dander, mold, and dust mites.
Allergic shiners can sometimes be caused by nasal congestion due to a sinus infection, cold, or flu, but this is less common than allergy causes.
When to see a doctor
If allergic shiners persist, whether accompanied by other symptoms or not, it is necessary to see a doctor to get a proper diagnosis.
Doctors may use the following methods when they diagnose allergies:
- a medical examination
- medical history and evaluation of symptoms
- blood tests
- skin prick tests to test for specific allergens
It is also important to see a doctor for allergic shiners if:
- they occur along with another condition, such as asthma or sleep apnea
- symptoms affect daily activities and quality of life
- symptoms include a high fever
- pain is experienced in the sinus area
- substances coming out of the nose are green
- symptoms do not improve with over-the-counter allergy medications
The treatment for allergic shiners is the same as for other symptoms of allergies. It is aimed at reducing congestion in the nasal and sinus cavities.
Treatment options include:
- Avoiding the allergen: Where possible, someone should try not to come into contact with the allergy trigger. This is the most important step in relieving symptoms.
- Antihistamine medications: Over-the-counter antihistamines, such as diphenhydramine (Benadryl) and loratadine (Claritin), can reduce allergy symptoms.
- Decongestant nasal sprays: These reduce swelling and pressure in the nasal airways and are available as pills or sprays. They should not be used for more than 3 days as they can lead to symptoms returning. Examples of sprays include oxymetazoline and neo-synephrine.
- Decongestant eyedrops: These drops, such as naphazoline (Clear Eyes) and tetrahydrozoline (Visine), provide relief from itchy and watery eyes. Similarly to decongestant nasal sprays, these drops can cause symptoms to return if used for more than 3 days.
- Prescription medications: If the above steps do not work, a doctor may prescribe stronger versions of these drugs. One example is montelukast (Singulair), which reduces the inflammation caused by exposure to allergens. Children can experience nightmares as a side effect, although this is rare.
People with severe allergies or allergies that do not respond to other treatments may benefit from immunotherapy.
It can take several years to complete immunotherapy treatment, which involves exposing the body to allergen extracts that allows it to build up tolerance gradually to the allergen.
Immunotherapy comes in two forms. either injectable treatment or sublingual treatment. Sublingual treatment involves a dissolvable tablet given orally over time. It is at least equal in effectiveness to injectable treatment.
People should be aware that many health insurers may not cover sublingual therapy if injectable therapy is available.
Saline eyedrops can help to clear the eye of allergens, and may prevent allergic shiners from occuring.
Preventing allergic shiners involves preventing allergic reactions from being triggered.
To prevent nasal allergy symptoms, people can take the following steps:
- recognize and avoid allergy triggers where possible
- use HEPA filters in air conditioners and vacuum cleaners
- wash all linen and upholstery with hot water every few weeks
- add moisture to the air with a humidifier
- use a nasal saline spray daily to loosen mucus and clear allergens from the nose
- use saline eyedrops to clear allergens from the eyes
- stay hydrated by drinking water, warm herbal teas, and other clear liquids
- flush out the nasal passages daily with a nasal rinse bottle or neti pot
Depending on the specific allergy triggers, there are other prevention measures that can be taken as well as the above.
For outdoor triggers
- keep the windows closed during allergy season and use air conditioning instead
- stay indoors on windy days when mold spores may be around or days when pollen counts are high
- remove shoes at the front door to avoid tracking allergens into the house
- shower and change clothing after going outside in allergy season
- wear sunglasses to keep pollen out of the eyes and cover the mouth with a scarf if possible
- do not dry clothing outside where it can pick up pollens
- mow the grass often, or have someone else do it
- wear a pollen or dust mask when gardening
- clear piles of leaves and grass cuttings from the garden
- keep gutters and drains clear to avoid mold growth
For indoor triggers
- treat mold and fungus in the home and clean mold-prone surfaces regularly
- clear up water damage as it occurs
- open bathroom windows or run the fan after showering to avoid condensation and mold growth
- use vent fans in the kitchen after cooking
- invest in allergy-proof covers for mattresses and bedding
- wash all bedding and children's soft toys weekly in hot water
- remove carpets from the home
- dust and vacuum the house regularly
- wash hands after contact with animals
- do not allow pets into the bedroom
- trap and remove cockroaches
Allergic shiners are a symptom of nasal allergies, but they are not usually considered serious.
With the proper treatment, allergic shiners should resolve in a matter of weeks. However, the symptom may return upon further exposure to the allergen.
As a result, it is vital to identify the allergen responsible and take steps to avoid or limit exposure to it to prevent future allergic shiners and other allergy symptoms.