A rare disease can cause extreme sensitivity to cold

For most people, cold weather is just an everyday nuisance and can be managed by putting on an extra layer of clothing or turning up the thermostat. But for some people, exposure to the cold can cause an allergic reaction so severe that it can even cause a person to fall to the ground.

Cold urticaria is a rare but potentially dangerous disease in which exposure to low temperatures disrupts the body’s immune system. The result of this disorder can be hives, swelling, pain, and in some cases, life-threatening anaphylaxis.

This disease was first described in 1792 by a German doctor named Johann Peter Frank. Today, it is known that its prevalence in women is almost twice that of men, and the average age of onset of the disease is in the early twenties, although this disorder can occur at any age.

However, there is also some hopeful news. Between 24% and 50% of people with cold urticaria recover or even recover completely over the years.

This disease is divided into two types. Primary cold urticaria is the most common type and accounts for about 95% of cases, and often no specific cause is identified. The remaining 5% are classified as secondary cold urticaria, which is associated with underlying diseases or infections; including Epstein-Barr virus, some types of lymphoma, HIV and hepatitis C.

Primary cold urticaria usually causes skin rashes, swelling, bumps, or hives, although some patients also complain of fatigue, fever, and joint pain. Symptoms often appear when the skin is exposed to cold, but may also occur when the skin is rewarmed.

Except for a few very rare genetic causes, the reason why some people develop primary cold urticaria remains unknown. What has been definitely determined is the role of our cells. These cells act as primary guards in the body’s tissues, including the skin, and alert the immune system to danger signs or pathogens.

It is not yet clear what exactly causes the activation of mast cells in cold urticaria. One of the hypotheses is that contact with cold causes the production of substances known as auto-allergens in the body.

When mast cells are activated, they release a chemical called histamine. Histamine acts like a warning siren that calls other immune cells to the target site. This substance also causes blood vessels to dilate and increase their permeability, which results in swelling, redness and itching.

Normally, this response is beneficial because increased blood flow and vascular permeability allow immune cells to leave the bloodstream and infiltrate surrounding tissue to deal with a real threat. But in cold urticaria, this is a false alarm.

To diagnose cold urticaria, doctors place an ice pack on the patient’s forearm and check the skin reaction after removing it. This disease is relatively rare and affects about 6 out of 10,000 people. However, it is likely that cases remain undiagnosed because not all sufferers have severe symptoms and in some countries, especially tropical regions, the temperature in winter does not usually fall below zero degrees Celsius.

After the diagnosis of the disease, it is very important to help the affected people to avoid the stimulating temperatures or to identify them.