Update on Urticaria and Angioedema.

Urticaria and angioedema are caused by immunoglobulin E- and non-immunoglobulin E-mediated release of histamine and other inflammatory mediators from mast cells and basophils. Diagnosis is made clinically, and anaphylaxis must be ruled out if urticaria or angioedema is present. A limited nonspecific laboratory workup should be considered unless elements of the history or physical examination suggest specific underlying conditions. The mainstay of treatment is avoidance of triggers when and if triggers are identified. The first-line pharmacotherapy is second-generation H1 antihistamines, which can be titrated to greater than standard doses.

Overexposure to ultraviolet radiation in solar urticaria.

A man in his 50s was diagnosed with solar urticaria following monochromated light testing that demonstrated exquisite photosensivity to ultraviolet (UV) A, UV B (UVB) and visible light.Treatment options for this photodermatosis are limited; UVB phototherapy is one modality that can be appropriate in some patients. This is administered at very low doses in a controlled environment to induce skin hardening.1 To self-treat his condition, the patient used a commercial sunbed on two occasions several days apart. He noted an immediate flare of solar urticaria after first use with associated dizziness. Following the second use, he felt generally unwell and was witnessed to lose consciousness and displayed jerky movements of his limbs while a passenger in a car. Investigations including a head MRI and an EEG were normal; an anoxic seizure caused by a flare of solar urticaria was later confirmed.Solar urticaria is a rare photodermatosis that is poorly understood and difficult to treat. The condition has a significant impact on the quality of life of patients. Severe cases can be associated with systemic symptoms that could be life-threatening.

The role of the environment in allergic skin disease.

PURPOSE OF REVIEW: This paper explores how environmental factors influence allergic skin diseases, including atopic dermatitis (AD), contact dermatitis (CD), urticaria, angioedema, and reactions to drugs and insect bites. RECENT FINDINGS: Research indicates a significant impact of environmental elements on allergic skin diseases. High air pollution levels exacerbate symptoms, while climate change contributes to increased skin barrier dysfunction, particularly affecting AD. Allergen prevalence is influenced by climate and pollution. Irritants, like those in detergents and cosmetics, play a major role in CD. Plants also contribute, causing various skin reactions. Understanding the interplay between environmental factors and allergic skin diseases is crucial for effective management. Physicians must address these factors to support patient well-being and promote skin health amidst environmental changes.

Acetylcholinesterase is regulated by exposure of ultraviolet B in skin keratinocytes: A potential inducer of cholinergic urticaria.

Cholinergic urticaria is a dermatological disease characterized by the presence of large patches of red skin and transient hives triggered by factors, such as exercise, sweating, and psychological tension. This skin problem is hypothesized to be attributed to a reduced expression of acetylcholinesterase (AChE), an enzyme responsible for hydrolyzing acetylcholine (ACh). Consequently, ACh is thought to the leak from sympathetic nerves to skin epidermis. The redundant ACh stimulates the mast cells to release histamine, triggering immune responses in skin. Here, the exposure of ultraviolet B in skin suppressed the expression of AChE in keratinocytes, both in in vivo and in vitro models. The decrease of the enzyme was resulted from a declined transcription of ACHE gene mediated by micro-RNAs, that is, miR-132 and miR-212. The levels of miR-132 and miR-212 were markedly induced by exposure to ultraviolet B, which subsequently suppressed the transcriptional rate of ACHE. In the presence of low level of AChE, the overflow ACh caused the pro-inflammatory responses in skin epidermis, including increased secretion of cytokines and COX-2. These findings suggest that ultraviolet B exposure is one of the factors contributing to cholinergic urticaria in skin.

Overview of Dermatological Manifestations Associated with the COVID-19 Infection.

COVID-19 is an infectious disease caused by SARS-CoV-2 that is characterized by respiratory symptoms, fever, and chills.[1] While these systemic symptoms are widely known and well understood, there have also been reports of dermatological manifestations in patients with COVID-19. These manifestations include chilblain-like lesions, maculopapular lesions, urticarial lesions, necrosis, and other varicella-like exanthems.[2] The pathogenesis of these lesions are not well understood, but the procoagulant and pro-inflammatory state induced by COVID-19 infections may be contributing to varied cutaneous manifestations.[3] Drug interactions and concurrent hypersensitivity reactions have also been postulated.[4] This review aims to compile and analyze various retrospective studies and case reports to summarize the clinical presentation of dermatological lesions associated with COVID-19 infections and suggest further areas of research.

Clinical Features and Outcomes of Acute versus Chronic Urticaria Triggered by COVID-19 Infection.

OBJECTIVE: Although acute urticaria (AU) and urticaria-like rash are commonly reported with COVID-19 infection, chronic spontaneous urticaria (CSU) triggered by COVID-19 is rare. The authors compared the features of COVID-19 infection-induced chronic CSU and AU to determine which patients' COVID-19 infection leads to CSU and possible indicators of chronicity. METHODS: The authors retrieved the charts of patients diagnosed with AU or CSU following COVID-19 at the Urticaria Centers of Reference and Excellence and compared patients in terms of demographic characteristics, length of time between infection and onset of urticaria, duration of urticaria, COVID-19 disease severity, laboratory test results, vaccination, and treatment status. RESULTS: A total of 92 patients were included in the study: 7 with CSU following COVID-19 and 85 with AU after COVID-19. The mean duration of urticaria for CSU and AU following COVID-19 was 13.0 ± 6.0 months and 7.1 ± 3.4 days, respectively. The average time between COVID-19 and the start of urticaria was longer in the CSU group (20.7 ± 3.9 days vs 4.5 ± 2.8 days, respectively; P = .000). No between-group differences were found for any other parameters. CONCLUSIONS: The onset of urticaria more than 2 weeks after COVID-19 infection may serve as an indicator for urticaria chronicity beyond 6 weeks and may help physicians predict the possible course of urticaria associated with COVID-19 infection. The relevance of basopenia and eosinopenia needs to be determined.

Cold-induced anaphylaxis triggered by drinking cold water.

Cold urticaria is an inducible urticaria in which hives and angioedema appear after exposure to cold. The symptoms of cold urticaria often are limited to hives/angioedema. However, in up to 20% of cases, cold exposure may trigger anaphylaxis. We report the case of an 11-year-old boy previously diagnosed with chronic spontaneous urticaria who developed facial swelling, itchy hives, difficulty in breathing, vomiting and abdominal pain within 5 minutes of drinking cold water. He received a standard dose of non-sedating second-generation antihistamines at home. He was observed in the emergency room for 2 hours and discharged with an epinephrin autoinjector. During the subsequent outpatient clinic visit, an ice cube test was performed which confirmed the new diagnosis of comorbid cold-induced chronic urticaria. On further questioning, the parents reported occurrence of hives following swimming in the swimming pool. Cold-induced urticaria should be suspected in cases of anaphylaxis associated with cold exposure. Patients with chronic forms of urticaria who present with new anaphylaxis should be assessed for a potential concomitant cold-induced form.

[Which augmentation and trigger factors are relevant in urticaria?] / Welche Augmentations- und Triggerfaktoren sind bei der Urtikaria relevant?

The aim of this review is to present relevant trigger as well as augmentation factors that can induce or exacerbate urticaria on the basis of a current, PubMed-based literature search. In addition to a brief description of relevant influencing factors in acute and chronic inducible urticaria, the focus will be on chronic spontaneous urticaria. In particular, the aggravating role of medication, stress, food, psychological and metabolic comorbidities, infections and inflammation as well as hormonal processes will be discussed.

A rare case of dialysis associated reaction presenting with urticarial vasculitis and haemoglobinuria.

Dialysis associated reactions presenting with urticarial vasculitis is rarely reported in medical literature. We report a 61-year-old gentleman who developed sudden onset dyspnea with diffuse erythema within 20 min of haemodialysis. Patient was started on Azilsartan 3 days prior to this clinical event. Labs revealed features of hemolysis and urine was positive for hemoglobinuria. All dialysis related factors responsible for this reaction were ruled out. Due to non-resolution of skin rash, skin biopsy was attempted which revealed fibrinoid necrosis of occasional vessels with predominant lymphocytic infiltration suggestive of drug induced urticarial vasculitis. Complement levels were normal. He was managed with steroids, anti-histaminic, discontinuation of azilsartan and change of dialyzer membrane. This case highlights a rare dermatological presentation of Type A dialysis associated reaction involving azilsartan with differential diagnosis and treatment strategies.

Urticaria in infants: A single-institution retrospective study.

Urticaria in infants can cause significant anxiety in parents, especially if a trigger cannot be identified. In a retrospective study of 246 infants seen for urticaria of unknown etiology at Boston Children's Hospital, 88.2% had resolution of urticaria within 6 weeks. The etiology of urticaria was ultimately established in 62.6% (72/115) of acute urticaria and 12.5% (2/16) of chronic urticaria cases with follow-up data. Pediatric healthcare providers can counsel families that while etiology of urticaria is never determined in over 40% of infants, symptoms are most likely to resolve spontaneously.

Cold urticaria as a complication of cryotherapy in the treatment of viral warts.

Cryotherapy with liquid nitrogen has been established as the first-line treatment for pediatric patients with viral warts. Cold-induced urticaria (CU) is a rare skin reaction triggered by cold stimuli. We present the case of a pediatric patient with viral warts who developed CU after receiving cryotherapy.

Tick bites, IgE to galactose-alpha-1,3-galactose and urticarial or anaphylactic reactions to mammalian meat: The alpha-gal syndrome.

The recent recognition of a syndrome of tick-acquired mammalian meat allergy has transformed the previously held view that mammalian meat is an uncommon allergen. The syndrome, mediated by IgE antibodies against the oligosaccharide galactose-alpha-1,3-galactose (alpha-gal), can also involve reactions to visceral organs, dairy, gelatin and other products, including medications sourced from non-primate mammals. Thus, fittingly, this allergic disorder is now called the alpha-gal syndrome (AGS). The syndrome is strikingly regional, reflecting the important role of tick bites in sensitization, and is more common in demographic groups at risk of tick exposure. Reactions in AGS are delayed, often by 2-6 h after ingestion of mammalian meat. In addition to classic allergic symptomatology such as urticaria and anaphylaxis, AGS is increasingly recognized as a cause of isolated gastrointestinal morbidity and alpha-gal sensitization has also been linked with cardiovascular disease. The unusual link with tick bites may be explained by the fact that allergic cells and mediators are mobilized to the site of tick bites and play a role in resistance against ticks and tick-borne infections. IgE directed to alpha-gal is likely an incidental consequence of what is otherwise an adaptive immune strategy for host defense against endo- and ectoparasites, including ticks.