Introduction

Cold-induced urticaria is a prevalent form of chronic inducible urticaria characterised by the body's response to cold exposure. This medical condition occurs when the skin encounters cold objects, water, or air, leading to specific symptoms. While relatively uncommon, cold-induced urticaria can significantly impact the lives of those affected. It represents a subset of chronic urticaria cases, accounting for approximately 25% of them, with 6% to 35% of individuals experiencing symptoms of cold urticaria. This article delves into various aspects of this chronic illness, including its prevalence, symptoms, diagnostic methods, treatment options, and strategies for reducing the risk of this condition. Additionally, it discusses prevention methods. 

Cold-induced urticaria

Cold-induced urticaria is a medical condition characterised by the development of hives (physical urticaria), a disorder that often appears as itchy, bumps (welts) on the surface when the skin is exposed to cold stimuli such as objects, water or air.^1,2 Among all cases of chronic urticaria, physical urticaria makes up 25%, and within this, 6% to 35% of individuals exhibit cold urticaria.³ Cold-induced urticaria is reported to occur at an estimated rate of 0.05%, and it tends to be more prevalent in countries with colder climates.⁴ The occurrence rate is approximately the same between men and women. While it is more prevalent among young adults ages 20 to 30 years, it can affect individuals across a wide age range, spanning from 3 months to 74 years. On average, the duration of this chronic urticaria ranges from 4.8 to 9.3 years, with approximately 50% of individuals experiencing improvements within 5 years.⁵

Cold-induced urticaria can be categorised into two main types:

• Immediate cold-induced urticaria: In this type, symptoms occur rapidly within minutes after cold exposure.
• Delayed cold-induced urticaria: This type has a delayed onset of symptoms, typically several hours after exposure to cold.

Understanding cold-induced urticaria

Cold-induced urticaria often presents with distinct skin reactions known as hives. These hives can vary in shape and size. In addition to skin reactions, cold-induced urticaria can give rise to systemic symptoms, some of which can pose potentially life-threatening risks, including the possibility of anaphylaxis and even fatalities when large areas of the body are exposed to the cold.⁶ Systemic symptoms can manifest as a combination of widespread local exposure and generalised urticaria, along with symptoms like skin flushing, headaches, chills, dizziness, a rapid heart rate (tachycardia), abdominal pain, nausea, vomiting, muscle aches (myalgia), shortness of breath, wheezing, and, in extreme cases, loss of consciousness.¹

The disease mechanism involves the activation of mast cells in the skin. When the body is exposed to cold, these mast cells release histamines and other inflammatory mediators. Histamines, in particular, play a central role in the development of hives and itching by causing blood vessels in the affected areas to expand and become more permeable. This phenomenon represents an immune response to the cold stimulus.⁷

How is cold-induced urticaria diagnosed?

A healthcare professional typically diagnoses cold-induced urticaria using the cold stimulation test (CST), commonly known as the ice cube test. During this test, a cold stimulus, such as an ice cube, is applied to the skin for 5-10  minutes. Afterwards, the skin is allowed to rewarm for 5-10 minutes. If a raised, reddish mark (weals), indicative of hives, appears during this period, the result is considered positive. The test may be repeated at shorter intervals to determine the minimum time required for symptoms of cold-induced urticaria to manifest. Conversely, a negative result is defined as the absence of symptoms developing after 5-10 minutes; however, this may be indicative of an atypical form of cold-induced urticaria, sometimes referred to as delayed cold-induced urticaria.⁵

The treatment options for cold-induced urticaria

The most effective way to prevent cold-induced urticaria is to avoid the cold which normally requires no treatment, self-limiting, if the symptoms are mild. However, if symptoms persist, then there are a range of treatment options available:⁷

1. Antihistamines: Non-sedating antihistamines, such as loratadine, cetirizine, or fexofenadine, are often prescribed to reduce itching and hives. They help block the effects of histamine released during an allergic reaction.
2. Leukotriene inhibitors: Medications like montelukast may be used to prevent the release of inflammatory substances, including leukotrienes, which can contribute to symptoms.
3. Epinephrine auto-injectors: Individuals with a history of severe reactions, including anaphylaxis, may be prescribed an epinephrine auto-injector. This should be carried out at all times and used in case of a severe allergic reaction.
4. Immunosuppressive Medications: In rare and severe cases of cold-induced urticaria that do not respond to other treatments, corticosteroids or other immunosuppressive medications may be considered. These drugs have potential side effects and are typically used as a last resort. 
5. Desensitisation therapy: Some individuals may undergo desensitisation therapy, where they are gradually exposed to cold temperatures under controlled conditions to reduce their sensitivity over time. This approach should only be performed by specialists.

Prevention

There are several ways to help avoid or minimise the risk of cold-induced urticaria: 

• Dress warmly: Wear layered clothing in cold weather to maintain body warmth. Cover as much of your skin as possible, including extremities like hands and feet.
• Stay indoors during extreme cold: When temperatures drop significantly, it's advisable to avoid exposure to extreme cold.
• Limit cold water contact: Avoid activities like swimming in cold water or taking cold showers, as they can trigger symptoms.
• Protect your face and neck: Use scarves, face masks, and turtleneck clothing to cover sensitive areas like the face and neck when facing cold weather.
• Prevent wind exposure: Wind can exacerbate the effects of cold, so use windbreakers or sheltered areas when windy conditions are present.
• Avoid direct skin contact with cold objects: Handle cold objects with gloves or other protective barriers to prevent direct skin contact.
• Limit outdoor activities in cold conditions: If you enjoy outdoor activities, try to engage in them during milder weather conditions or use appropriate protective clothing.
• Keep medications handy: Carry any prescribed medications, such as antihistamines or an epinephrine auto-injector, if recommended by your healthcare provider, in case of an allergic reaction.

Summary

Cold-induced urticaria is a unique medical condition characterised by the development of hives and itching when the skin is exposed to cold stimuli. It represents a subset of chronic urticaria cases, affecting approximately 25% of them. It has a broad age range of onset, from 3 months to 74 years, with an average duration of 4.8 to 9.3 years, and about 50% of patients experience improvement within 5 years.

There are two main forms: immediate and delayed, with the potential for severe reactions, including anaphylaxis. The condition's mechanism involves mast cells in the skin releasing histamines and inflammatory mediators in response to cold exposure.

Diagnosis is typically made through the cold stimulation test (CST), and treatment options include antihistamines, leukotriene inhibitors, epinephrine autoinjectors, and, in rare cases, immunosuppressive medications. Preventive measures involve dressing warmly, avoiding extreme cold, and protecting exposed skin from cold contact.

Understanding the triggers, symptoms, diagnosis, and treatment of cold-induced urticaria can help individuals effectively manage their condition and improve their quality of life.