Diagnosis and treatment of solar urticaria

Phototherapy in the Evaluation and Management of Photodermatoses

Ultraviolet light (UV) and visible light are important components in the diagnosis of photodermatoses, and UV has the unique ability to also be used to manage photodermatoses. Phototesting, provocative light testing, and photopatch testing can provide important information in diagnosing patients with photodermatoses; phototesting can be used to determine the starting dose for phototherapy in these patients. Once photosensitivity is established, narrowband UVB and UVA1 therapy have helped to improve the quality of life of photosensitive patients, such as those with polymorphous light eruption, chronic actinic dermatitis, and solar urticaria.

Solar urticaria - An Australian case series of 83 patients

Solar urticaria (SU) is a rare form of urticaria with a pathogenesis that is poorly understood. It affects all skin types, can be difficult to diagnose, and is challenging to manage effectively. We conducted a retrospective review of patients with SU in our institution. A total of 83 patients (56 females) were identified as having SU. The mean age was 32 years (7-74) at first development of symptoms/signs of SU. Pruritus was the most common symptom reported (79%). Of the 60 patients who underwent monochromator testing at least once, 35 had SU confirmed with most reacting to visible light and UVA, or to UVA alone. Antihistamines and sun avoidance remain the mainstay treatment for SU but other treatments, including omalizumab, are of potential interest in treating patients with recalcitrant SU. The characterisation of this large case series of patients may help dermatologists recognise and manage this rare disorder appropriately.

Infrared radiation increases skin damage induced by other wavelengths in solar urticaria

BACKGROUND

Photodermatoses are typically investigated by analyzing the individual or combined effects of ultraviolet A (UVA), ultraviolet B (UVB), and visible light using light sources that simulate portions of the solar spectrum. Infrared radiation (IRR), however, accounts for 53% of incident solar radiation, but its effects are not taken into account in standard phototest protocols.

AIMS

The aim was to analyze the effects of IRR, alone and combined with UVA and visible light on solar urticaria lesions, with a distinction between infrared A (IRA) and infrared B (IRB).

METHODS

We performed standard phototests with UVA and visible light in four patients with solar urticaria and also tested the effects after blocking IRB with a water filter. To analyze the direct effect of IRR, we performed phototests with IRA and IRB.

RESULTS

Initial standard phototests that were all positive found the induction of erythema and whealing, while when IRR was blocked from the UVA and visible light sources, three of the patients developed no lesions, while the fourth developed a very small wheal.

CONCLUSION

These results suggest that IRR has the potential to produce and exacerbate lesions caused by other types of radiation. Consideration of these effects during phototesting could help prevent diagnostic errors.

Review of Physical Urticarias and Testing Methods

PURPOSE OF REVIEW

This review aims to update the information available on the prevalence, clinical picture, diagnostic methods, and treatment of urticarias induced by external physical stimuli.

RECENT FINDINGS

Physical urticarias are present in up to 5% of the general population, and in 10 to 50% of patients with chronic urticaria. Recent investigations have provided evidence that the presence of physical urticaria alone or when comorbid with chronic spontaneous urticaria is associated with a worse prognosis and duration. Most frequent subtypes of physical urticaria are dermographism and delayed pressure urticaria. The diagnosis is established through specific provocation tests and the management encompasses avoidance measures, pharmacologic therapy with nonsedating antihistamines, and alternative medications in refractory cases.

Narrowband ultraviolet B phototherapy is a suitable treatment option for solar urticaria

BACKGROUND

Narrowband (NB) ultraviolet (UV) B lamps are widely used for treatment and prophylaxis of several skin diseases.

OBJECTIVE

We sought to assess the efficacy of two protocols of NB-UVB therapy for the prophylaxis of UVB-sensitive and UVB-insensitive solar urticaria (SU).

METHODS

Subjects affected by SU underwent phototesting for assessment of the minimal erythemal dose and minimal urticarial dose. Patients without urticarial response to UVB underwent a single daily exposure every other day for 4 weeks (group A). Patients with a urticarial test response to broadband UVB or NB-UVB (group B) received 3 daily exposures (on working days) for the first week. Afterward, they were treated as the patients of group A for 3 weeks. Follow-up visits took place after 1 and 3 months.

RESULTS

A total of 39 patients completed the study. In groups A (29 patients) and B (10 patients), the median total number of exposures was 12 (interquartile range [IQR]: 12; 15) and 25.5 (IQR 24; 27), respectively. The median total NB-UVB dose was 10.3 J/cm(2) (IQR 9.9; 11) for group A and 9.1 J/cm(2) (IQR 8.5; 10.6) for group B. At follow-up visits, patients reported good tolerance to the sun.

LIMITATIONS

A direct comparison of NB-UVB with UVA or psoralen plus UVA for the photoprophylaxis of SU is still lacking.

CONCLUSION

NB-UVB phototherapy was well-tolerated and effectively prevented SU relapses.

EAACI/GA(2)LEN/EDF/WAO guideline: management of urticaria

This guideline, together with its sister guideline on the classification of urticaria (Zuberbier T, Asero R, Bindslev-Jensen C, Canonica GW, Church MK, Giménez-Arnau AM et al. EAACI/GA(2)LEN/EDF/WAO Guideline: definition, classification and diagnosis of urticaria. Allergy 2009;64: 1417-1426), is the result of a consensus reached during a panel discussion at the Third International Consensus Meeting on Urticaria, Urticaria 2008, a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA(2)LEN), the European Dermatology Forum (EDF) and the World Allergy Organization (WAO). As members of the panel, the authors had prepared their suggestions regarding management of urticaria before the meeting. The draft of the guideline took into account all available evidence in the literature (including Medline and Embase searches and hand searches of abstracts at international allergy congresses in 2004-2008) and was based on the existing consensus reports of the first and the second symposia in 2000 and 2004. These suggestions were then discussed in detail among the panel members and with the over 200 international specialists of the meeting to achieve a consensus using a simple voting system where appropriate. Urticaria has a profound impact on the quality of life and effective treatment is, therefore, required. The recommended first line treatment is new generation, nonsedating H(1)-antihistamines. If standard dosing is not effective, increasing the dosage up to four-fold is recommended. For patients who do not respond to a four-fold increase in dosage of nonsedating H(1)-antihistamines, it is recommended that second-line therapies should be added to the antihistamine treatment. In the choice of second-line treatment, both their costs and risk/benefit profiles are most important to consider. Corticosteroids are not recommended for long-term treatment due to their unavoidable severe adverse effects. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS).

Chronic idiopathic urticaria: prevalence and clinical course

The purpose of our study was to assess the prevalence and clinical course of patients with chronic idiopathic urticaria (CIU), as well as possible causes or associated findings, laboratory findings and the duration of the disease in patients with chronic urticaria (CU). We retrospectively reviewed the 450 case record forms of patients with CU and/or angioedema who attended the Department of Dermatology, Siriraj Hospital, during the period 2000-2004. Of 450 patients with CU, 337 patients (75%) were diagnosed as CIU. Forty-three patients (9.5%) had physical urticaria, while 17 patients (3.8%) had infectious causes. Other possible causes were food, thyroid diseases, atopy, drugs, dyspepsia and collagen vascular diseases. In eighty-nine percent of patients, no abnormalities were detected at the time of physical examination. The most common abnormal laboratory finding was minimal elevation of the erythrocyte sedimentary rate (42%). In 61 patients, autologous serum skin tests had been done. Fifteen patients (24.5%) had positive results i.e. autoimmune urticaria. Anti-thyroglobulin and anti-microsomal antibodies were positive in 16 % and 12% of CIU patients respectively. After 1 year from the onset of the symptoms, 34.5% of CIU patients were free of symptoms and after 1.2 years from the onset of the symptoms, 56.5% of autoimmune urticaria patients were free of symptoms. The median disease duration of CIU and autoimmune urticaria were 390 days and 450 days respectively. Our study provided an overview of CU and CIU in a large series of Thai patients, based on etiological aspects and clinical courses.

Nichthereditäre Photodermatosen im Kindesalter

Non-hereditary photodermatoses with well-known trigger factors and idiopathic light eruptions occur quite frequently during childhood and are at least temporarily associated with a marked impairment of quality of life in affected patients and their parents. Thus, it is crucial that the involved specialties are familiar with acquired UV-associated disorders in order to guarantee a quick diagnosis and effective therapy. Additionally, the recurrence of photodermatoses associated with potentially severe long-term complications has to be prevented. This requires a stringent prophylaxis that can only succeed after age-adapted instruction of the patient and parents.

EAACI/GA2LEN/EDF guideline: management of urticaria

This guideline is the result of a consensus reached during a panel discussion at the second International Consensus Meeting on Urticara, Urticaria 2004, a joint initiative of the EAACI Dermatology Section and GA2LEN. Urticaria has a profound impact on the quality of life, and effective treatment is therefore required. The recommended first line treatment are nonsedating H1 antihistamines. They have proven to be effective in double-blind controlled studies, but dosages increased up to fourfold over the recommended doses may be necessary. However, for different urticaria subtypes and in view of individual variation in the course of the disease and response to treatment, additional or alternative therapies may be required. Immunosuppressive drugs like cyclosporin A and corticosteroids are not recommended for long-term treatment due to unavoidable severe adverse effects. This guideline was, in addition, accepted by the European Dermatology Forum (EDF) and formally approved by the European Union of Medical Specialists (UEMS).

Solar angioedema: an uncommonly recognized condition?

Solar urticaria is a well defined although uncommon photosensitivity disorder, and is said to be the underlying cause of chronic urticaria in approximately 0.5% cases. In contrast, solar angioedema is seldom reported. We describe two patients with postulated solar angioedema, associated with clinical and/or phototest features of solar urticaria. Recognition of solar provocation of angioedema has important consequences for patient management.

Urticaria solar. Estudio de 20 casos

INTRODUCTION

Solar urticaria is an infrequent disorder, but is probably underdiagnosed. It is characterized by the sudden appearance of weals in areas that are not usually photoexposed after exposure to the sun or to artificial sources of visible or ultraviolet light. Few cases have been published in literature, so the information available about this disorder and its natural evolution is limited.

MATERIAL AND METHODS

We have compiled data from 20 patients diagnosed with solar urticaria in our department in the last 12 years (1990-2002) in order to try to obtain information about the characteristics of this condition.

RESULTS

As the most relevant characteristics of our series, we can mention the fact that 60 % of the patients were women, and the average duration of the condition before consulting a dermatologist was 3 years. In 55 % of the patients, areas that are usually photoexposed, such as the face and hands, were less severely affected (due to acclimatization or hardening). The spectra responsible for the SU were visible light, UVA and UVB, in that order. With regard to treatment, we obtained a partial response with antihistamines and photoprotectors, and good results using progressive desensitization with UVA/sunlight.

CONCLUSION

Solar urticaria is probably an underdiagnosed condition in our milieu. There are few series in literature that provide any information about the most significant characteristics of this disorder. We have compiled the most relevant data from our patients and we have compared it with the other published series in an attempt to learn more about this photodermatosis.