Contact allergy to oxidised geraniol may be over-represented in individuals with photocontact allergy to ketoprofen.

BACKGROUND: Simultaneous overrepresentations of contact allergies and photocontact allergies are common in individuals with photocontact allergy to ketoprofen. AIMS: To investigate whether contact allergy to oxidised (ox.) geraniol, geraniol, geranial, neral and citral is overrepresented in individuals with photocontact allergy to ketoprofen. METHODS: The contact allergy rates to ox. geraniol, geraniol, geranial, neral and citral in routinely patch tested dermatitis patients were compared with the corresponding rates in individuals with photocontact allergy to ketoprofen. RESULTS: Allergic patch test reactions were noted to ox. geraniol 11% (n = 39, 5.8%), ox. geraniol 6% (n = 12, 1.8%), geraniol 6% (n = 2, 0.3%), geranial (n = 18, 2.7%), neral (n = 7, 1.0%) and citral (n = 15, 2.2%). In those four patients who were diagnosed with photocontact allergy to ketoprofen during the test period, a significant overrepresentation (p = 0.020) of simultaneous contact allergy to ox. geraniol 11% was demonstrated. Overrepresentation of simultaneous contact allergy to various combinations of ox. geraniol, ox. limonene and ox. linalool was also noted in ketoprofen-photoallergic patients. CONCLUSIONS: Contact allergy to ox. geraniol, geranial and citral is common in routinely tested dermatitis patients. There is an overrepresentation of simultaneous contact allergy to ox. geraniol, ox. limonene and ox. linalool in patients with photocontact allergy to ketoprofen.

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

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Contact Allergy to Oxidized Linalool and Oxidized Limonene is Over-represented in Individuals with Photocontact Allergy to Ketoprofen.

Simultaneous contact allergies are common in individuals with photocontact allergy to ketoprofen. The rate of contact allergy to the fragrance substances oxidized linalool and oxidized limonene in ketoprofen-photo-allergic individuals were investigated in comparison with the corresponding rates in individuals without photo-contact allergy to ketoprofen, using Fisher's exact test. A total of 4,021 patients were routinely tested with oxidized linalool; of whom 190 (4.7%) tested positively. For oxidized limonene the numbers were 3,797 patients and 111 positive reactions (2.9%). A total of 19 contact allergic reactions to oxidized linalool were noted in 29 patients (65.5%) who also had photocontact allergy to ketoprofen (p < 0.0001). The corresponding figures for oxidized limonene were 10 positive reactions in 24 ketoprofen-photoallergic individuals (41.7%) (p < 0.0001). Contact allergy to oxidized linalool and/or oxidized limonene is common in routinely tested patients with dermatitis and, particularly, in those patients who are photoallergic to ketoprofen.

Successful photopatch testing with ketoprofen using one-hour occlusion.

The standard procedure for photopatch testing includes 24-h occlusion of the allergen, followed by irradiation at 5 J/cm2 ultraviolet A (UVA). Due to the timing, a separate visit to the clinic is needed for UV irradiation. The aim of this study was to determine whether a reduction in occlusion time from 24 h to 1 h, in order to simplify the testing procedure, influences test results when photopatch testing with ketoprofen. A total of 22 patients with a known or suspected photo-allergy to ketoprofen were simultaneously photopatch-tested with ketoprofen using both 1 h and 24 h occlusion. One side of the patient's back was irradiated with 5 J/cm2 UVA, and the other side was covered. Measurements were made after 3 days on both irradiated and non-irradiated sides. A total of 20 controls were photopatch-tested with ketoprofen using 1 h occlusion. All of the patients showed positive reactions on the irradiated side. No positive reactions were observed on the non-irradiated side. All controls were negative. In conclusion, 1 h occlusion time is sufficient to establish photo-contact allergy to ketoprofen. No adjustments in UVA or ketoprofen dose were needed. Limiting occlusion time to 1 h could simplify the photopatch test procedure by eliminating one visit to the clinic. These results apply only to ketoprofen; further studies are needed to determine whether a similar approach can be used with other components of photopatch test series.