Photopatch Testing Research Articles

Photopatch testing: Clinical characteristics, test results, and final diagnoses from the North American Contact Dermatitis Group, 2009-2020.

Photoallergic contact dermatitis (PACD) is a delayed hypersensitivity reaction to allergens only in the presence of ultraviolet radiation in sunlight. Photopatch testing (PhotoPT) is necessary to confirm the diagnosis of PACD. There are few published studies of PhotoPT in North America. To summarise the results of patients photopatch tested by members of the North American Contact Dermatitis Group (NACDG), 2009-2020. Retrospective analysis of patient characteristics and PhotoPT results to 32 allergens on the NACDG Photopatch Test Series. Most of the 454 tested patients were female (70.3%), 21-60 years old (66.7%) and White (66.7%). There were a total of 119 positive photopatch tests. Sunscreen agents comprised 88.2% of those, with benzophenones responsible for over half of them. Final diagnoses included PACD in 17.2%, allergic contact dermatitis (ACD) in 44.5%, polymorphous light eruption (PMLE) in 18.9% and chronic actinic dermatitis (CAD) in 9.0% of patients. In 454 patients with suspected photosensitivity referred for photopatch testing in North America, approximately one-fifth had PACD. Sunscreen agents, especially benzophenones, were the most common photoallergens. Other common diagnoses included ACD, PMLE and CAD. Photopatch testing is an important tool for differentiating these conditions.

Investigations and treatment of photodermatoses

The photodermatoses comprise of a miscellaneous set of photosensitive disorders with abnormal cutaneous response to sunlight. The diagnosis is mostly clinical and is augmented by methods such as phototesting, photoprovocation testing, and photopatch testing, which are discussed below. Treatment includes photoprotection, prophylactic phototherapy, as well as topical and systemic immunosuppression to varying extents. Various newer modalities for photoprotection as well as treatment are being explored.

Clinical profile and photocontact sensitivity pattern in patients with cosmetic dermatitis: A prospective study.

Background With the rise in cosmetic usage, adverse reactions related to cosmetics have also risen. Photocontact dermatitis to cosmetics is a challenging entity to diagnose and manage. Objectives To evaluate the clinical features and photocontact sensitivity patterns in patients with cosmetic dermatitis and establish their association based on patch and photopatch test results. Methods A prospective observational study, where 80 patients with a clinical diagnosis of cosmetic dermatitis were patch or photopatch tested (as per indication) with the Indian standard series, Indian cosmetic and fragrance series, and the patient's personal product(s). Results A total of 104 positive reactions were observed in 57/80 patients, of which 50 were relevant to cosmetics usage. Sixty-five patients underwent a photopatch test, and 17 tested positive. Photosensitivity in patients was significantly associated with a positive photopatch test (p-value < 0.001). Various new photo-allergens were discovered, including propylene glycol, triethanolamine, chloroacetamide, isopropyl myristate, cetrimide and hexamine. Facial melanosis was a predominant clinical finding in 44 patients, with pigmented contact dermatitis detected in 19 (43.2%) of these cases. Limitations Patients' personal products could not be tested on every patient. Chemical analysis of indigenous products and the individual chemical ingredients of the patient's personal products could not be patch-tested separately. Phototesting was not performed in patients with photosensitivity. Conclusion In patients with suspected cosmetic dermatitis with history of photosensitivity or those with facial melanosis of unknown origin, a photopatch test is crucial to detect potentially hidden photo allergens. Many new photo allergens have emerged in the present study. Cosmetic companies should provide detailed information regarding each constituent of the cosmetic products.

Correlation of photopatch positivity with clinical profile in patients with photoallergic dermatitis

Photopatch test (PPT) is designed to diagnose Photoallergic Contact Dermatitis (PACD) using specific dose and wavelength of irradiation. This study is a retrospective analysis of patients with photosensitivity who have undergone photopatch testing. To find the Correlation of photo patch positivity with clinical profile in patients with photoallergic dermatitis. Photo patch testing helps in determining the sensitizing potentials of commonly used day to day agents containing the allergen. Thirty-seven patients who had patch tested between July 2022and June 2023 were analyzed. The patch test antigens comprising 20 common photoallergens from Indian Standard Series were photopatch tested. Of all the patients tested the overall positivity rate was (67.56%). All patients had a characteristic clinical picture of photodermatitis for an variable duration. All patients were engaged in various occupations that involved working outdoors. The exacerbating factors were summer season in 15 (40.54%) patients, insecticides spraying in three (8.1%) and exposure to plant in ten (27%). History of contact with cement was present in six (16.21%) patients. The patients who showed positivity after irradiation was 5 (13.51 %), before and after irradiation was 7 (18.91%), and exacerbated grading after irradiation was 13 (35.13%). The commom allergen showing positivity were parthenium (29.72%), potassium dichromate (13.51%), PPD (10.81%). Apart from these allergens’ fragrance mix, paraben, neomycin sensitivity was also noted in few patients. Significant number of cases belongs to photodermatitis, thereby, finding the cause and the measures to alleviate the symptoms are paramount important. For proper diagnosis, photopatch test is essential and our study emphasis the same which can aid in appropriate management. Cosmetics, sunscreens and drugs like NSAID are found to be the emerging cause for PACD and photopatch series with relevence to above allergen is the need of the hour.

A novel hydrogel-based moisturizing cream composed of hyaluronic acid for patients with xerosis: An intraindividual comparative analysis.

Hyaluronic acid (HA) is mainly used to treat xerosis. It also exerts wound-healing, moisturizing, and antiaging effects. Although HA is considered an effective and safe ingredient in cosmetics, there is a constant demand for a more money-saving and effective formulation. This study aimed to evaluate the safety and efficacy of a novel hydrogel-based moisturizer containing HA cross-linked with silicone polymers, produced solely through irradiation without the use of cross-linking agents. A safety study enrolled 30 participants with healthy skin to perform patch and photopatch tests while recording adverse events. For the efficacy study, 30 participants with xerosis were compared before and after using the novel hydrogel, evaluating the cutaneous barrier function, xerosis severity scale (XSS) score, participant's satisfaction, and Investigator's Global Assessment (IGA). Furthermore, the efficacy of the novel hydrogel-based moisturizer was evaluated by comparing it with a conventional moisturizer, Physiogel, in another 30 participants with xerosis. In the safety study, no serious adverse events were observed. In the efficacy study before and after use, skin hydration and skin surface lipid increased (p<0.05) whereas the XSS scores decreased (p<0.05) with time. In the comparative efficacy study with Physiogel, skin hydration increased whereas the XSS scores decreased (p<0.05) over time in both groups. Furthermore, IGA improved in 100% of participants in both groups. Also, 100% and 93% of participants were satisfied with the novel hydrogel-based moisturizer and Physiogel, respectively. The novel hydrogel-based moisturizer proved to be safe and effective for xerosis, showing comparable results to the conventional moisturizer.

Photopatch testing in Singapore: A 10-year retrospective study.

Photopatch testing represents the gold standard for the diagnosis of photoallergic contact dermatitis (PACD). We aimed to identify common photoallergens in our tertiary dermatological referral centre from 2012 to 2021, to compare this to the preceding period studied, and data from other communities. We conducted a retrospective review of all 90 patients who underwent photopatch testing at the National Skin Centre, Singapore, between 2012 and 2021. Of 90 patients, 19 (21.1%) were male, and the mean age was 41.6 years. Eighty-four (93.3%) underwent testing to our standard sunscreen series, 10 (11.1%) to our extended series, and 73 (81.1%) to their own items. Seventeen (18.9%) were diagnosed with PACD (i.e., photocontact allergy with present or past relevance), 12 (13.3%) with ACD, and 4 (4.4%) with photoaugmented ACD. Relevant reactions were commonest to oxybenzone (8, 9.5%) and mexenone (3, 3.6%). Eleven (15.1%) had PACD to their own items, with 3 of 4 (75%) tested to ketoprofen diagnosed with PACD and the remaining 1 (25%) with photoaugmented ACD. Age, race, sex, atopy, and site of involvement were not associated with photocontact allergy. Compared to the preceding time period, the overall frequency of photocontact allergy and PACD decreased, but rates of photoallergic reactions to individual photoallergens were not significantly different. Organic ultraviolet absorbers such as oxybenzone and mexenone remained the most relevant photoallergens. Personal item testing was valuable, and testing to ketoprofen should be considered.

Photosensitive dermatoses in paediatric practice

Photodermatoses represent a heterogeneous group of disorders characterized by the development of pathological skin reaction to solar radiation. The development or intensification of inflammatory skin reaction after exposure to ultraviolet or electromagnetic spectrum that is visible to the human eye is a distinctive feature of all photosensitive photodermatoses. Although photodermatoses are less common in children than in adults, they are often associated with genetic or congenital metabolic disorders, and may also point to diffuse connective tissue diseases. Paediatric photodermatoses are often the result of genetic or congenital metabolic disorders, and may also indicate diffuse connective tissue diseases. The epidemiological studies have showed that the global prevalence of photodermatoses diagnosed with photopatch tests is above or equal to 5.7%. The authors presented a modern classification of photosensitive dermatoses according to the etiological factor. The article provides up-to-date information about photosensitive dermatoses, including statistical epidemiological data, pathogenesis features, and also emphasis is placed on the issues of the quality of life of children and their parents. The authors described the clinical presentations of the most common paediatric photosensitive dermatoses and the basic principles of their therapy. Among topical glucocorticosteroids, methylprednisolone aceponate has proven itself in the treatment of paediatric photodermatoses as it has not only a pronounced anti-inflammatory effect, but also is easy-to-use. The timely diagnosis of paediatric photosensitivity will help to minimize the development of complications associated with delayed treatment and insufficient prevention (photoprotection).

Shedding a light on the importance of photopatch testing: A 12-year experience in a dermatology unit.

Photopatch testing has been standardized for diagnosing photoallergic contact dermatitis but is still infrequently used. To characterize photopatch test (PPT) results and their clinical relevance. We collected retrospective data from patients photopatch tested in our Dermatology Unit (2010-2021), using the European PPT 'baseline' series, other allergens, and patient's own products, when appropriate. Out of 223 patients, 75 patients (33.6%) were reactive with 124 positive PPT reactions, considered relevant in 56/223 patients (25.1%) and in 72/124 reactions (58.1%). Most reactions were caused by topical drugs (n= 33; 45.8%), such as ketoprofen or promethazine, and 7 (9.8%) by systemic drugs, such as hydrochlorothiazide and fenofibrate. 'Classical' ultraviolet filters were responsible for six positive PPT reactions whereas there was only three relevant PPT to the 'newer' UV filters. Patients' sunscreens/cosmetics or plant extracts caused 10 positive PPT each. Additional patch test reactions were observed, mostly to Tinosorb® M. Contrary to the trend in ACD, most positive PPT reactions were caused by topical drugs, outweighing ultraviolet filters and cosmetics. We stress the low reactivity to the 'newer' UV filters included in the PPT series. PPT was occasionally positive in systemic drug photosensitivity, but overall PPT reactivity was low.

A postulated model for photoimmunopathogenesis of chronic actinic dermatitis around adaptive immunity, including Th17 cells, Tregs, TRMs, cytotoxic T cells, and/or common-γ chain receptor+ cells.

The pathogenesis of chronic actinic dermatitis (CAD) is more complicated than other photodermatoses. However, the relationship between the clinical severity of CAD and the offending photocontact or contact allergens or both, and the correlations of CAD immunopathogenesis with the immunoregulatory molecules involved in adaptive immunity are yet to be investigated. We performed phototesting with broad-spectrum ultraviolet (UV) B, UVA, and visible light to establish the presence of photosensitivity in 121 patients with CAD, together with photopatch and contact patch testing. Nine patients with CAD were selected according to their clinical severity score for CAD (CSS-CAD), and triple direct immunofluorescence analysis was performed with paraffin-embedded skin biopsy samples. As CSS-CAD was closely correlated with the multiplicity of photo(contact) allergens, particularly photoallergens, three or more photoallergens were detected in the severe CAD group (52.5%); less in the moderate group (32.8%); and only one in the mild group (14.8%; P=.025). In the groups showing greater severity of disease, the absolute numbers of IFN-γ+ , IL-17+ , CD4+, CD8+, common-γ chain receptor (common-γCR)+ , and CD69+ tissue-resident memory cells increased on average; there was also an increase in the CD4+/CD8+ cell ratio, with the more severely affected groups. However, the levels of TNF-α+ and FoxP3+ regulatory T (Treg) cells and the mean IL-17/IFN-γ cell ratio decreased in the more severely affected CSS-CAD subgroups. Based on the clinical analysis and immunopathogenic results, avoidance of excessive sun exposure, and topical and systemic blocking agents for photo(contact) allergens are recommended. Additionally, conventional immunomodulators and emerging agents including JAK-STAT inhibitors may be administered for CAD treatment in the future.

Photoallergic Contact Dermatitis: No Fun in the Sun.

Photoallergic contact dermatitis (PACD) is a form of allergic contact dermatitis that occurs due to the interaction between a topically applied chemical and exposure to UV radiation. It can be difficult to identify and requires photopatch testing (PPT) for definitive diagnosis. In this article, we provide an overview of PACD, including clinical features, the most common photoallergens, and why cases may go undiagnosed.

Photosensitivity is an important cause of refractory facial erythema in atopic dermatitis: A retrospective study of 82 Chinese patients.

Ultraviolet radiation can aggravate facial erythema in atopic dermatitis (AD) patients. To investigate the photobiological testing results of Chinese AD patients with refractory facial erythema. We conducted a retrospective analysis of 82 AD patients with refractory facial erythema who visited our department during 2004-2021. All of them completed phototesting and photopatch testing. 82 patients were enrolled in the study, and 53 (64.6%) were between 18 and 30 years old. 51.2% (42/82) had positive phototesting results and were considered photosensitive AD (PhAD) patients. One-third of them were both allergic to ultraviolet A and ultraviolet B. 65.9% (54/82) suffered from photoallergic contact dermatitis. Chlorpromazine (50.7%), potassium dichromate (13.2%), and thimerosal (11.8%) were the top three common photoallergens. Overall, 86.3% of AD patients with refractory facial erythema had direct photoallergy or photocontact allergy. PhAD patients had fewer allergic comorbidities than the other group (p=.007). More non-PhAD patients (55.0%) suffered from AD at 2-14 years old (p=.015). Photosensitivity contributes a lot to the facial lesions of AD patients, especially in their 20s. 86.3% of these patients had direct photoallergy or photocontact allergy. Therefore, AD patients with facial erythema should undergo phototesting and photopatch testing routinely.

Safety and efficacy of a new hydrogel based on hyaluronic acid as cosmeceutical for xerosis.

Hyaluronic acid (HA) is among the most effective and safe ingredients frequently used in cosmetics. However, a more economical and efficient formulation is still required. We sought to assess the safety and efficacy of a novel hydrogel manufactured only by irradiation containing cross-linked HA and polyethylene glycol polymers with addition of polysiloxane. The study included 30 people with normal skin and 30 patients with xerosis. In the normal skin group, to evaluate the safety, a patch test and a photopatch test were performed, and patients' discomfort was investigated. In those with xerosis, to assess the efficacy, a skin barrier function test was performed at baseline and at 2, 4, and 8 weeks after the application of the novel hydrogel. Additionally, the xerosis severity scale (XSS), patient satisfaction, Investigator's Global Assessment (IGA), and adverse responses were evaluated. In the safety study, there was no significant discomfort in the experimental group compared with the control group. In the efficacy study, at 2, 4, and 8 weeks after the application of the novel hydrogel, the mean value of skin hydration and sebum content increased and the mean value of XSS decreased with time in the experimental group, and a difference was observed when compared with the control group. IGA showed improvement in 97%, 77%, and 80% at each visit and the proportions of satisfied patients were 90%, 87%, and 90%, respectively. The novel HA-based hydrogel tested herein could be a safe and effective therapeutic remedy for xerosis.

33863 Successful use of dupilumab for treatment of atopic dermatitis in a liver transplant patient

There is a paucity of data regarding the use of dupilumab treatment of atopic dermatitis (AD) in solid organ transplant patients. We report a case of successful treatment of AD in an orthotopic liver transplant (LT) patient with dupilumab with favorable clinical response and no observed side effects throughout two years of treatment. A 65-year-old Caucasian female with history of orthotopic LT for cirrhosis 17 year prior, presented to dermatology clinic with 2-year history of a pruritic eruption involving bilateral extremities. Punch biopsy revealed spongiotic dermatitis with eosinophils, consistent with atopic dermatitis, allergic contact dermatitis, or id reaction. Photo-patch testing revealed positivity for methyldibromo glutaronitrile, benzalkonium chloride, and benzophenone. Despite numerous trials of medium- and high-potency topical steroids as well as intramuscular and oral corticosteroids, the patient experienced continued pruritus and repeated flares. Phototherapy and immunosuppressives including methotrexate and cyclosporine were contraindicated due to the patient’s photo-allergy and LT status on a stable dose of tacrolimus, respectively. After extensive discussion with the patient’s primary care and transplant teams, the decision was made to begin dupilumab. After 1 month of treatment, the patient experienced near clearance of rash, minimal flares that were easily controlled with adjunct topical corticosteroids, and a 90% improvement in subjective pruritus, with no adverse effects. This response was sustained throughout an additional 2 years of treatment. We report this case of successful dupilumab treatment of AD in a LT patient to raise awareness to the safety and efficacy of its use in this patient population.

Clinicophotobiological Characterization of Photoaggravated Atopic Dermatitis

Photoaggravated atopic dermatitis (PAD) is estimated to affect 1.4% to 16% of patients with AD but remains poorly characterized with limited published data. To provide detailed clinical and photobiological characterization of PAD. This case series study used cross-sectional data collected from 120 consecutive patients diagnosed with PAD from January 2015 to October 2019 at a tertiary center referral unit for photobiology. Routinely collected standardized clinical and photobiological data were analyzed using descriptive statistics, and regression analysis explored associations between demographic and clinical data. Of 869 patients who underwent photoinvestigation, 120 (14%) were diagnosed with PAD (69 female [58%]; median age, 45 [IQR, 31-61] years; range, 5-83 years; skin phototypes [SPTs] I-VI). Of these patients, 104 (87%) were adults. All patients had a history of AD, and most (62 of 104 [60%]) presented with sunlight-provoked or photodistributed eczema; median age at photosensitivity onset was 37 years (range, 1-72 years). Past-year Dermatology Life Quality Index score was greater than 10 for 80 of 103 adults (78%), and 82 of 119 (69%) had vitamin D (25-hydroxyvitamin D) level insufficiency or deficiency (<20 ng/mL; to convert ng/mL to nmol/L, multiply by 2.496). Broadband UV radiation provocation test results were positive for 112 patients (93%). In 28 patients (23%) with abnormal monochromator phototest findings, sensitivity occurred to UV-A, UV-B, and/or visible light, and UV-A of 350 ± 10 nm was the most prevalent wavelength. Photopatch test reactions were positive for 18 patients (15%). Patients with SPTs V to VI (31 [26%]) vs SPTs I to IV (89 [74%]) were younger at photosensitivity onset (median age, 24 years [IQR, 15-37 years] vs 40 years [IQR, 25-55 years]; P = .003), were more likely to be female (23 [74%] vs 46 [52%]; P = .03), and had a lower vitamin D status and a higher frequency of abnormal monochromator phototest findings. In this case series study, PAD affected patients with different ages and SPTs and was associated with substantially impaired quality of life. The findings suggest that confirming PAD through phototesting may provide better personalized care for patients through identification of provoking wavelengths, relevant photocontact allergies, and appropriate photoprotection advice.

Translated article] What Dermatologists Should Know About Thiazides

Hydrochlorothiazide and other thiazide diuretics have been used for decades to treat high blood pressure, heart failure, and chronic kidney disease. Thiazides have been linked to photosensitivity with heterogeneous clinical manifestations and recovery times. Diagnosis can be aided by phototesting, photopatch testing, and skin biopsy. Long-term use of hydrochlorothiazide has been linked to an increased dose-dependent risk of certain types of skin cancer in recent years. In this review, we also look at other less common or lesser-known adverse effects of thiazide diuretics that have been described in isolated reports.

The role of patch and photopatch tests in facial melanoses: A cross-sectional, observational study

Background: Facial pigmentation includes various entities such as melasma, lichen planus pigmentosus (LPP), and pigmented contact dermatitis. The pathogenesis may involve certain allergens, which may be responsible for causing a disturbance in the dermoepidermal junction. The elimination of such inciting allergens may aid in the successful treatment of these patients. Objective: The aim was to detect contact allergens with patch and photopatch testing in facial pigmentary disorders. Methods: Fifty patients with facial pigmentary disorders were enrolled. After taking a demographic profile and detailed clinical history and performing an examination, patch and photopatch testing was done using a common suspected allergen series. Results: Out of the fifty patients tested, 28 (56%) showed a positive patch test, while 2 (4%) showed a positive photopatch test. The most common allergen found was a fragrance mix in 17 (34%) patients, followed by paraphenylenediamine (PPD) in 11 (22%). Other allergens showing positivity were nickel sulfate, benzocaine, parthenium, benzophenone-3, octyl methoxycinnamate, etc. Conclusion: Patients with facial pigmentation may have an underlying component of contact dermatitis, which may be a causative or aggravating factor. The avoidance of these allergens may help in increasing the efficacy of treatment in these patients.

Tiazidas: lo que el dermatólogo debería saber

Hydrochlorothiazide and other thiazide diuretics have been used for decades to treat high blood pressure, heart failure, and chronic kidney disease. Thiazides have been linked to photosensitivity with heterogeneous clinical manifestations and recovery times. Diagnosis can be aided by phototesting, photopatch testing, and skin biopsy. Long-term use of hydrochlorothiazide has been linked to an increased dose-dependent risk of certain types of skin cancer in recent years. In this review, we also look at other less common or lesser-known adverse effects of thiazide diuretics that have been described in isolated reports.

To check contact dermatitis contagion and health hazardous: A review

Skin is the largest organ of our body when it is exposed to exogenous irritants and allergens in 24hours, these noxious agents’ cause immunotoxicity, and Contact dermatitis (CD) is one of them. Here in this review we had checked its types, main causes, Action mechanisms of irritants and allergens, Clinical aspects and its management: diagnostic tests, preventions and treatments of this contagion. There are two types of CD: first is the Irritant contact dermatitis (ICD) and second one is Allergic contact dermatitis (ACD). ICD is exposure of skin by physiological, biological, and chemical toxins resulting into rupturing of stratum corneum and release of cytokines which show inflammatory response. ACD is the interaction of xenobiotics with immune system. It is basically the immunotoxicity by chemicals which is developed by two phases (1) induction and (2) elicitation. Phototoxic and photo allergic CD is developed when CD is due to sunlight exposure. Management of CD is including (1) primary prevention: by avoidance or preventions at different levels (2) secondary prevention: when skin is affected by chemicals then diagnoses is very necessary by Patch test and photo Patch test(3)Tertiary prevention: treatment should be done as soon as possible by steroids and other products.

Photoallergic reaction to cephalosporin: Hitherto unreported

Photoallergic reactions are Type IV hypersensitivity reactions localized to photo-exposed areas, with generalization in severe cases. Diagnosis is based on history, photo-patch testing and clinico-histopathological correlation. A 47-year-old man developed multiple, erythematous plaques over V-area of neck, retroauricular area, extensor aspect of both forearms after oral cefixime post-cholecystectomy. He had similar episode of lesser severity two months ago after oral Cefixime. Histopathology showed acanthotic epidermis, foci of spongiosis causing vesiculation with lymphocytes. Upper dermis showed infiltrate of lymphocytes and neutrophils along with perivascular infiltrate. Diagnosis was photoallergic reaction to Cefixime. Lesions completely subsided with oral steroids, hydroxychloroquine, antihistamines, sunscreen and emollients over two months. Cephalosporins have multiple side-effects including hypersensitivity, rash, Steven–Johnson syndrome and toxic epidermal necrolysis. Cephalosporin induced photoallergy is not reported. Hence, cephalosporins should be added to the existing list of systemic drugs causing photoallergic reactions.

Contact allergy to fragrance mix I and its components in individuals with photocontact allergy to ketoprofen.

Contact allergy to fragrance mix I (FM I) is over-represented in patients photoallergic to ketoprofen. The prevalence of contact allergy to two components of FM I, cinnamal and cinnamyl alcohol, in ketoprofen-photoallergic patients is higher than in dermatitis patients. To explore the prevalence of contact allergy to FM I and its individual components in patients with photocontact allergy to ketoprofen, and to compare with a dermatitis and the general population. Data on patch and photopatch tests performed between 2009-2018 were collected. Ketoprofen-photoallergic patients were compared with dermatitis patients and published data on the general population regarding the prevalence and the distribution of contact allergy to FM I and its components. A higher prevalence of contact allergy to cinnamyl alcohol compared with cinnamal (23.3% vs 10.0%), and eugenol compared with isoeugenol (23.3% vs 6.7%), was observed in ketoprofen-photoallergic patients, while the relationship was the opposite in the dermatitis group (0.7% vs 1.05%; 0.4% vs 0.9%). The overall prevalence of contact allergy to several components of FM I was significantly higher in ketoprofen-photoallergic patients. Contact allergy to FM I and many of its components is over-represented in patients photoallergic to ketoprofen compared with dermatitis patients and the general population.