Photogenic sneezing syndrome: causes, risks, and treatment methods

Have you ever stepped out of a dark tunnel or dimly lit room into bright sunlight, only to find yourself suddenly bursting into involuntary sneezing? If your answer is yes, you are not alone, and there is no need to worry; you are simply suffering from what is known as “photic sneezing syndrome”.

This condition, scientifically known as the phototic sneeze reflex , is a complex and intriguing physiological response affecting a significant percentage of the population. According to the Gulf Health Council , this phenomenon occurs as a result of sudden exposure to bright light, which stimulates the nervous system to trigger a series of sneezing episodes.

Historical background and scientific facts about the phenomenon

Although some might think it's a recently discovered phenomenon, photic sneezing has intrigued scientists and philosophers since ancient times. The Greek philosopher Aristotle, in his book "Problems," wondered why people sneeze when looking at the sun, suggesting at the time that the sun's heat was the cause, before modern science proved that light, not heat, is the primary trigger.

Global studies indicate that this syndrome affects between 18% and 35% of the world's population. Scientists affectionately call it Achoo Syndrome, and it is a dominant genetic trait, meaning that if one parent has it, there is a 50% chance that their children will also inherit it.

Causes of photic sneezing

The exact cause is still under investigation, but the most widely accepted theory among scientists relates to interference of neural signals, and possible causes include the following:

• Interference of nerve signals: Scientists believe there is a neural “interference” between the optic nerve (responsible for vision and light perception) and the trigeminal nerve (responsible for sensation in the face and nose). When exposed to bright light, the optic nerve sends a strong signal to constrict the pupils. Due to the close proximity of the two nerves, the trigeminal nerve may pick up on this signal and misinterpret it as irritation in the nose, leading to sneezing.
• Genetic factor: As we mentioned, genes play a crucial role in the transmission of this trait across generations.
• Nervous system hypersensitivity: an exaggerated response of the nervous system to strong visual stimuli.

Symptoms of photic sneezing syndrome

This syndrome is characterized by a range of symptoms that appear immediately upon exposure to the light stimulus:

• Sudden and uncontrollable sneezing when moving from darkness to light (such as exiting a cinema or tunnel).
• A tingling or itching sensation in the nose immediately preceding sneezing.
• Consecutive bouts of sneezing that may range from two to ten sneezes at a time.
• Watery eyes and temporary visual discomfort.

Risks and consequences (locally and globally)

Although photic sneezing is classified as a benign health phenomenon and not a serious illness, it may pose risks in specific situations that require high attention:

• The risk of traffic accidents: This is the most significant risk, especially when exiting dark tunnels into bright daylight. A series of sneezes can cause a driver to lose vision and control for several crucial seconds, potentially leading to traffic accidents.
• Flight safety: For military or civilian pilots, photic sneezing is a factor to consider when flying towards the sun, as it can affect concentration at critical moments.
• Social embarrassment: Frequent sneezing fits can cause discomfort in formal social situations.

Diagnosis and prevention methods

Diagnosis is usually based on the patient's medical history and observation of symptoms, while ruling out other allergens. As for prevention, the following tips can be followed to reduce the severity of attacks:

• Wearing sunglasses: Using high-quality sunglasses with UV protection before going out in the sun greatly helps in blocking the strong light stimulus.
• Hats: Wear a wide-brimmed hat to block direct sunlight from your eyes.
• The philtral pressure technique: Place your finger and apply moderate pressure to the area between your nose and upper lip (the philtrum) as soon as you feel the urge to sneeze. This movement has proven effective in stopping the sneezing signal for some people.
• Gradual exposure to light: Try not to look directly at the light source when moving from a dark environment to a bright one.