Acquired primary cold contact urticaria after Hymenoptera sting

Cold Urticaria Syndromes: Diagnosis and Management

Cold urticaria is a chronic condition causing episodic symptoms of cold-induced wheals or angioedema in response to direct or indirect exposure to cold temperatures. Whereas symptoms of cold urticaria are typically benign and self-limiting, severe systemic anaphylactic reactions are possible. Acquired, atypical, and hereditary forms have been described, each with variable triggers, symptoms, and responses to therapy. Clinical testing, including response to cold stimulation, helps define disease subtypes. More recently, monogenic disorders characterized by atypical forms of cold urticaria have been described. Here, we review the different forms of cold-induced urticaria and related syndromes and propose a diagnostic algorithm to aid clinicians in making a timely diagnosis for the appropriate management of these patients.

Cold urticaria - What we know and what we do not know

Cold urticaria (ColdU) is a common form of chronic inducible urticaria characterized by the development of wheals, angioedema or both in response to cold exposure. Recent research and guideline updates have advanced our understanding and management of ColdU. Today, its pathophysiology is thought to involve the cold-induced formation of autoallergens and IgE to these autoallergens, which provoke a release of proinflammatory mediators from skin mast cells. The classification of ColdU includes typical and atypical subtypes. We know that cold-induced wheals usually develop on rewarming and resolve within an hour and that anaphylaxis can occur. The diagnosis relies on the patient's history and cold stimulation testing. Additional diagnostic work-up, including a search for underlying infections, should only be done if indicated by the patient's history. The management of ColdU includes cold avoidance, the regular use of nonsedating antihistamines and the off-label use of omalizumab. However, many questions regarding ColdU remain unanswered. Here, we review what is known about ColdU, and we present important unanswered questions on the epidemiology, underlying pathomechanisms, clinical heterogeneity and treatment outcomes. Our aim is to guide future efforts that will close these knowledge gaps and advance the management of ColdU.

Review of cold-induced urticaria characteristics, diagnosis and management in a Western Canadian allergy practice

Background

Cold-induced urticaria is a significant condition, especially among young females. Despite the morbidity of this disease, studies that fully characterize the disease are limited.

Methods

We analyzed the characteristics of patients diagnosed with cold-induced urticaria at a community-based allergy practice in Vancouver, BC, Canada between 2003 and 2016. Detailed patient history, diagnostic measures and treatment were evaluated.

Results

A total of 50 patients were found to have active cold-induced urticaria with a median age of 28.5 (range 2-67) years and 35 patients (70%) were female. 16 patients (32%) had co-occurring physical urticarias while 26 patients (52%) had secondary allergic diagnoses and 3 patients (6%) were thought to have a provoking factor. Of those with a clinical history of suspected cold-induced urticaria that were evaluated with ice cube testing, a positive test was obtained in 84.7% of patients. Treatment was largely with non-sedating antihistamines, with the majority of patients receiving this modality.

Conclusions

Cold-induced urticaria is a complex disease with significant overlap with other chronic inducible urticarias and other allergic diseases. Diagnostic testing shows inconsistent results and the mainstay of treatment consists of non-sedating antihistamines, with other options available for those who do not respond.

Modern approaches to the diagnosis and treatment of cold contact urticaria

Cold contact urticaria (CCU) is a common subtype of physical urticaria characterized by itchy wheals and/or angioedema due to skin mast cell activation and the release of proinflammatory mediators after cold exposure. The underlying causes are largely unknown. When CCU is suspected, cold stimulation tests and threshold testing should be done to confirm the diagnosis and to determine the severity and course of CCU, respectively. Avoidance of critical cold exposure should be recommended but is often impossible, especially for severely affected patients with high temperature and low exposure time thresholds. Symptomatic treatment of choice is the use of modern, nonsedating antihistamines. Patients should be informed that complete protection from CCU symptom development may require increased doses of antihistamines. Standardizing cold provocation tests and further characterization of the natural course of CCU and its variants may lead to a better understanding of the disease-driving mechanisms.

Acquired cold urticaria: clinical picture and update on diagnosis and treatment

Acquired cold urticaria (ACU) is a frequent subtype of physical urticaria that is caused by the release of proinflammatory mast cell mediators after cold exposure. Although the underlying causes of ACU still remain to be clarified in detail, a wide range of diseases has been reported to be associated with ACU. This review gives an overview of the clinical picture, the differential diagnoses, diagnostic tests and the aetiology of ACU, and summarizes current and novel therapeutic options based on the current literature.

Clinical reactivity to insect stings

PURPOSE OF REVIEW

Allergy to insect stings remains a hazard worldwide and is the object of updated guidelines on management. This paper reviews the various clinical responses that may occur following an insect sting.

RECENT FINDINGS

Although the general population is at slight risk, certain groups are more susceptible, including occasionally stung adult male agricultural workers, hobby honey beekeepers and family members of beekeepers. Individuals with systemic mastocytosis are especially reactive to stings. The body of evidence attesting to the marked beneficial effect that 3-5 years of venom immunotherapy has on the natural history of hymenoptera hypersensitivity is especially evident in children. Case reports indicate other consequences of hymenoptera sting, and these are discussed.

SUMMARY

Hypersensitivity to insect stings is common and may be life threatening. Although most occur away from medical facilities, their diagnosis and management are important to a wide spectrum of health care professionals. Most reactions to stings are nonallergic manifestations of the venom's toxic effects, and present as erythema, pain and swelling about the sting site. Fire ants bite with their mandibles and pivot their head, inflicting multiple stings that usually result in a sterile pseudopustule at the site. Hypersensitivity responses to venom range from large local reactions (a late-phase response) to life-threatening anaphylaxis. Venom-specific immunotherapy is highly effective in the modification of subsequent reactions to hymenoptera stings, as is whole body extract for fire ant stings.