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.     

Validation of the diagnostic criteria for atopic dermatitis in the adult Thai population

Atopic dermatitis is a chronic inflammatory skin disorder, for which it is difficult to obtain epidemiologic findings. In a previous study, we suggested the following diagnostic criteria for atopic dermatitis in the adult Thai population: visible flexural dermatitis, a history of flexural dermatitis, a rash of more than six months duration and visible dry skin. However these criteria were not validated against physicians' diagnoses. In the present study, we validated these diagnostic criteria for atopic dermatitis in the Thai population in a clinical setting. A case-controlled study was performed on a total of 259 patients; 33 subjects with active atopic dermatitis, 26 with inactive atopic dermatitis, 100 controls presenting with an inflammatory skin disorder other than atopic dermatitis and 100 controls without any skin disease. Each patient was examined according to the above criteria. Sensitivity, specificity, relative value, positive predictive value, and negative predictive value were calculated for each individual criterion and for composite criteria. Our data confirmed that in order to achieve satisfactory sensitivity and specificity for diagnosing atopic dermatitis in Thai people older than 13 years, a patient must have a history of flexural dermatitis plus two or more of the other mentioned criteria.     

Comparative identification of protein profiles and major allergens of saliva, salivary gland and whole body extracts of mosquito species in Thailand

Allergic reactions to mosquito bites, such as generalized urticaria or severe local reactions are common problems worldwide. The diverse sources of allergen prepared from different mosquito body parts usage are a major obstacle to obtaining safe and effective tests and immunotherapy for mosquito bite allergy. Thus, the reactions are often not recognized and allergen immunotherapy is seldom used for severe reaction to mosquito bites. In a search for appropriate allergen sources, the protein profiles of saliva, salivary glands and whole body extracts were comparatively analyzed from 4 common mosquito species of Thailand and/or South East Asia; viz. Culex quinquefasciatus, Aedes aegypti, Aedes albopictus and a zoophilic strain, Anopheles minimus. The major allergens in the extracts which elicited specific IgE responses in the pooled sera of subjects allergic to mosquito bites were identified. It was concluded that mosquito saliva was the best source of allergens. Additionally, both species-specific and species-shared allergens of the 4 mosquito species were identified. The major saliva allergens having MWs of 36, 32 and 22 kDa were identified. The identificstion of major allergens should facilitate the production of specific recombinant allergens and contribute to improvement in the diagnosis and specific immunotherapy of Thai mosquito bite allergy patients.     

South‐East Asia study alliance guidelines on the management of acne vulgaris in South‐East Asian patients

The management of acne in South‐East Asia is unique, as Asian skin and local variables require a clinical approach unlike that utilized in other parts of the world. There are different treatment guidelines per country in the region, and a group of leading dermatologists from these countries convened to review these guidelines, discuss current practices and recent advances, and formulate consensus guidelines to harmonize the management of acne vulgaris in the region. Emphasis has been placed on formulating recommendations to impede the development of antibiotic resistance in Propionibacterium acnes. The group adopted the Acne Consensus Conference system for grading acne severity. The group recommends that patients may be treated with topical medications including retinoids, benzoyl peroxide (BPO), salicylic acid, a combination of retinoid and BPO, or a combination of retinoids and BPO with or without antibiotics for mild acne; topical retinoid with topical BPO and a oral antibiotic for moderate acne; and oral isotretinoin if the patient fails first‐line treatment (a 6‐ or 8‐week trial of combined oral antibiotics and topical retinoids with BPO) for severe acne. Maintenance acne treatment using topical retinoids with or without BPO is recommended. To prevent the development of antibiotic resistance, topical antibiotics should not be used as monotherapy or used simultaneously with oral antibiotics. Skin care, comprised of cleansing, moisturizing and sun protection, is likewise recommended. Patient education and good communication is recommended to improve adherence, and advice should be given about the characteristics of the skin care products patients should use.     

Prevalence and relevance of the positivity of skin prick testing in patients with chronic urticaria

Many patients with chronic urticaria (CU) worry that foods or other allergens are responsible for their urticaria. Skin prick testing (SPT) may be one of the investigations used to provide a clear illustration. The purpose of our study was to assess the prevalence of positivity of SPT to food allergens and aeroallergens and their relevance in patients with CU, in order to demonstrate the diagnostic value of SPT in CU. We retrospectively reviewed case record forms of patients with chronic ordinary urticaria who underwent SPT in the Urticaria Clinic, Siriraj Hospital, during the period 2000-2004. The studied allergens included 16 food allergens and 12 aeroallergens. Eighty-eight patients were enrolled. The prevalence of positive SPT among patients with CU was 47.7%. Patients who had personal histories of atopy had statistically significant positive SPT results compared with patients who had negative SPT. Of 88 patients, 26 patients (30%) gave positive results to food allergens, 36 patients (41%) gave positive results to aeroallergens and 20 patients (22.7%) gave positive results to both food and aeroallergens. One-third of the subjects (34.6%) who had positive SPT results to food allergens had clinical relevance of food allergy in some systems but only one patient had clinical relevance of food-induced urticaria. Half of the patients who had a history of aeroallergen sensitivity gave a positive SPT response for aeroallergens; however, there was no clinical relevance to their CU. Our study showed that the prevalence of positive SPT to food allergens and aeroallergens in patients with CU was common but had little clinical relevance to CU.     

Arthrography and arthrotomy of the knee in sports injuries.

A total of 266 patients with injuries to the knee sustained during sports activities were managed by arthroscopy and/or arthrotomy. All of them received systemic examination and a standard battery of knee stability tests. Fifty-three were examined by arthrography and all underwent arthrotomy for surgical correction of the lesion diagnosed by both clinical examination and arthrography. Our study showed that clinical examination could give an accurate clinical diagnosis in 88.35% of cases and arthrography in 76.89%. No complication from arthrography was found. Injury occurred most commonly between 21 and 30 years of age and was more common to the right knee than the left. The sport in which most injuries occurred was football.     

Variations in abductor pollicis longus and extensor pollicis brevis tendons in the Quervain syndrome: a surgical and anatomical study.

Eighty-two wrists of Thai cadavers and the wrists of 66 patients with de Quervain syndrome were studied, and the variation in the number of tendons and the fibro-osseous tunnel in the first extensor compartment were recorded. The abductor pollicis longus had more than one tendon in 73 of the cadavers (89%) and in 32 of the patients (49%) (p <0.001). The extensor pollicis brevis was a single tendon in 80 (98%) and 62 (94%) of cadavers and patients, respectively. There was division with the septum that made a fibro-osseous tunnel in the first extensor compartment in 30/82 (37%) cadavers and in 38/66 (58%) patients with de Quervain syndrome (p = 0.01). The results indicate that the number of fibro-osseous tunnels and multiple compartments in the first extensor compartment may be associated with a predisposition to de Quervain syndrome.     

Autoimmune and rheumatic manifestations and antinuclear antibody study in HIV-infected Thai patients

BACKGROUND: There have been reports concerning an association between human immunodeficiency virus (HIV) infection and autoimmune and rheumatic diseases. OBJECTIVE: The purpose of this study was to examine autoimmune and rheumatic manifestations in HIV-infected patients and their correlation with antinuclear antibody (ANA) tests. METHODS: The clinical and laboratory results of HIV-infected patients attending the Department of Dermatology, Siriraj Hospital, Bangkok, Thailand, from February 1999 to January 2000, were analyzed. Laboratory studies included serum CD4 lymphocyte count and ANA tests. RESULTS: Sixty-two patients were enrolled prospectively in the study. Myalgia was the most common clinical presentation (50%). Others included photosensitivity (on history) (39%), arthralgia (26%), vasculitis (18%), sicca complex (10%), arthritis (7%), and Reiter's syndrome (2%). A history of hair loss was given by 23% of patients. A positive ANA test was detected in 3%. No cases of systemic lupus erythematosus, scleroderma, or dermatomyositis were seen. CONCLUSIONS: Autoimmune and rheumatic manifestations were not uncommonly detected in patients with HIV infection. HIV infection may sometimes mimic systemic lupus erythematosus clinically.