Allergic and photoallergic contact dermatitis from ketoprofen: results of (photo) patch testing and follow-up of 42 patients

Probing skin photoallergens in reconstructed human epidermis: An EPR spin trapping investigation

Photoallergic contact dermatitis is a skin disease caused by combined exposure to photoreactive chemicals and sunlight. Exposure to allergens and the risk of skin sensitization is an essential regulatory issue within the industry. Yet, only few non-validated assays for photoallergy assessment exist as the pathogenesis is not fully deciphered. Improving such assays and/or developing new ones require an understanding of the chemical mechanisms involved. The first key event in the photosensitization process, namely chemical binding of the photoallergen to endogenous proteins, is thought to proceed via photo-mediated radicals arising from the photoallergen. Moreover, the mechanism of action of these radicals if formed in the epidermis is not known and far from being unraveled. We present here an original proof-of-concept methodology to probe radical generation from allergens in contact with photoexposed skin, using electron paramagnetic resonance and spin trapping in a reconstructed human epidermis model mimicking real-life exposure scenarios.

Fragrance Contact Allergy - A Review Focusing on Patch Testing

Fragrance materials are widely used in various types of products in daily life and many of them can be contact sensitizers. Contact allergy to fragrances has been reported to be common worldwide. Unlike other groups of contact allergens such as metals and preservatives, fragrance materials in consumer products can be present as single fragrance chemicals or in the form of mixtures known as natural complex substances. Due to the complexity of the fragrance materials and the high number of fragrance substances known to cause contact sensitization, selecting suitable materials for patch testing is challenging. Emerging fragrance markers have been additionally introduced in different baseline series for screening to enhance the rate of fragrance contact allergy detection. Moreover, there have been continual updates on basic knowledge, clinical perspectives, sources of exposure, and regulations on the use of fragrance materials. Avoiding pitfalls while performing patch testing with fragrance test materials is also crucial and should not be overlooked. Therefore, this review aims to update knowledge to provide a high-quality holistic approach to fragrance contact allergy diagnosis and management.

[Translated article] Allergic Contact Dermatitis to Topical Ophthalmic Drugs: Review of Frequently Used Allergens in Spain

Allergic contact dermatitis induced by the use of ophthalmic topical drugs is one of the most common causes of eyelid dermatitis. The introduction of new formulations, both of active ingredients and excipients, and the lack of marketing in some of them, makes patch testing in patients whose source of contact are topical ophthalmic drugs truly challenging. Across this manuscript, most, if not all, topical ophthalmic drugs used in our national health system have been collected, including information on the allergens available, and the concentration and vehicle advised for those that still remain unavailable.

Allergic Contact Dermatitis to Topical Ophthalmic Drugs: Review of Frequently Used Allergens in Spain

Allergic contact dermatitis induced by the use of ophthalmic topical drugs is one of the most common causes of eyelid dermatitis. The introduction of new formulations, both of active ingredients and excipients, and the lack of marketing in some of them, makes patch testing in patients whose source of contact are topical ophthalmic drugs truly challenging. Across this manuscript, most, if not all, topical ophthalmic drugs used in our national health system have been collected, including information on the allergens available, and the concentration and vehicle advised for those that still remain unavailable.

Photochemical Reaction of Ketoprofen with Proteinogenic Amino Acids

Ketoprofen (KP) is one of the most popular nonsteroidal anti-inflammatory drugs; however, drug-induced photosensitivity of KP has been reported as a serious adverse effect. KP incorporated into a protein can produce an allergen under UV irradiation, which causes drug-induced photosensitivity. The photochemistry of KP with 20 kinds of proteinogenic amino acids in phosphate buffer solutions at pH 7.4 was studied by transient absorption spectroscopy. The KP carboxylate anion (KP^-) gave rise to a carbanion via a decarboxylation within a laser pulse, and the carbanion yielded 3-ethylbenzophenone ketyl biradical (3-EBPH) through a proton transfer reaction. Twelve kinds of proteinogenic amino acids obviously accelerated the reaction. Structural information on the complexes of KP docked in the binding sites of human serum albumin (HSA) was obtained by molecular mechanics (MM) and molecular dynamics (MD) calculations. The photochemical reaction of KP^- with amino acid residues in HSA was discussed on the basis of the experimental and calculational results. The information on the reactivity of KP with the amino acids and the stable structures of the KP-HSA complexes should be essential for understanding of the initial step for drug-induced photosensitivity.

A new case of photoallergic contact dermatitis caused by benzophenones in magazine covers

BACKGROUND

Allergic contact dermatitis (ACD) and photoallergic contact dermatitis (PACD) to benzophenone present in printing ink have been reported. However, precise chemical analyses and extended photo-patch tests have not been performed in these cases.

OBJECTIVES

To determine which component present in a magazine cover are responsible for a patient's skin reaction, determine the primary sensitiser and precisely diagnose ACD and PACD PATIENT AND METHODS: After initial photopatch tests were performed on a patient with a history of reaction to magazine covers after sun exposure, gas chromatography-mass spectrometry and high-performance liquid chromatography analyses of the magazine covers and additional photopatch tests were performed.

RESULTS

The first photopatch test results confirmed PACD to ketoprofen and fenofibrate, and evoked PACD to the magazine covers. 4-methyl benzophenone (4-MBP) and 1-hydroxy-cyclohexyl-phenyl-ketone (1-HCPK) were found in the magazine cover. Additional photopatch tests confirmed PACD to 1-HCPK and to benzophenone, and photo-aggravated ACD to 4-MBP. The primary sensitiser was ketoprofen.

CONCLUSIONS

Benzophenones are present in a wide variety of products, without always being listed on the packaging. Patients previously sensitised to other ketones, such as ketoprofen, may react to benzophenones without being able to avoid contact with these molecules. New regulations may be needed for more efficient eviction advice. This article is protected by copyright. All rights reserved.

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 dermatitis

Contact dermatitis (CD) is among the most common inflammatory dermatological conditions and includes allergic CD, photoallergic CD, irritant CD, photoirritant CD (also called phototoxic CD) and protein CD. Occupational CD can be of any type and is the most prevalent occupational skin disease. Each CD type is characterized by different immunological mechanisms and/or requisite exposures. Clinical manifestations of CD vary widely and multiple subtypes may occur simultaneously. The diagnosis relies on clinical presentation, thorough exposure assessment and evaluation with techniques such as patch testing and skin-prick testing. Management is based on patient education, avoidance strategies of specific substances, and topical treatments; in severe or recalcitrant cases, which can negatively affect the quality of life of patients, systemic medications may be needed.

The presence of benzophenone in sunscreens and cosmetics containing the organic UV filter octocrylene: A laboratory study

BACKGROUND

The reason why patients photosensitized to the drug ketoprofen (KP) may develop severe photoallergic skin reactions to octocrylene (OCT), an organic ultraviolet filter in sunscreens and cosmetics, remains largely unknown. OCT can be synthesized by using unsubstituted benzophenone (BP), a possible human carcinogen.

OBJECTIVES

To verify if, and to what extent, BP residues are present in OCT-containing consumer products.

METHODS

The raw material of OCT and 39 skincare products, of which 28 contain OCT, were chemically analysed for the presence of BP by means of liquid chromatography.

RESULTS

In the OCT raw material and in all 28 OCT-containing products the presence of BP could be demonstrated, mostly in concentrations above 10 ppm (0.001%), whereas a majority of OCT-free products (8/11, 73%) did not contain BP. Moreover, BP concentrations significantly increased, in a time- and temperature-dependent manner, likely due to the additional degradation of OCT.

CONCLUSIONS

Photoallergic contact dermatitis from OCT in patients photosensitized to KP might rely on residual BP impurities. Toxicological and ecological studies that evaluate the safety of OCT might also need to consider the concomitant presence of BP.

Photosensitivity and cancer immune-targeted therapies

The novel group of immunological agents used for solid tumors has importantly improved the quality of life and the survival rate of oncologic patients. Compared to conventional chemotherapy agents, they are more effective and less toxic. However, adverse cutaneous effects are commonly observed, and in some cases, they may induce treatment discontinuation, with heavy impact on patient prognosis. Among these, photosensitive reactions, either phototoxic or photoallergic, are increasing. Much remains to be clarified on the understanding of their prevention, diagnosis, and management. We have reviewed the literature about photosensitive reactions occurring during oncologic immunotherapies. Early dermatological diagnosis and adequate management, with oncologist's cooperation, is fundamental.

Photostability Issues in Pharmaceutical Dosage Forms and Photostabilization

Photodegradation is one of the major pathways of the degradation of drugs. Some therapeutic agents and excipients are highly sensitive to light and undergo significant degradation, challenging the quality and the stability of the final product. The adequate knowledge of photodegradation mechanisms and kinetics of photosensitive therapeutic entities or excipients is a pivotal aspect in the product development phase. Hence, various pharmaceutical regulatory agencies, across the world, mandated the industries to assess the photodegradation of pharmaceutical products from manufacturing stage till storage, as per the guidelines given in the International Conference on Harmonization (ICH). Recently, numerous formulation and/or manufacturing strategies has been investigated for preventing the photodegradation and enhancing the photostability of photolabile components in the pharmaceutical dosage forms. The primary focus of this review is to discuss various photodegradation mechanisms, rate kinetics, and the factors that influence the rate of photodegradation. We also discuss light-induced degradation of photosensitive lipids and polymers. We conclude with a brief note on different approaches to improve the photostability of photosensitive products.

Photopatch testing in Bogota (Colombia): 2011-2013

BACKGROUND

Photopatch tests are used to diagnose photoallergic contact dermatitis and identify the causal agents. The frequencies of positive results and associated allergens vary by country; therefore, it is necessary to know the information specific to each country.

OBJECTIVE

To establish the frequency of positive photopatch test results, and their relevance, in patients with suspected photoallergic contact dermatitis in a national dermatology centre located in Bogota, Colombia.

MATERIALS AND METHODS

One hundred patients investigated for possible photoallergic contact dermatitis were enrolled in the study. They were photopatch tested with a selected group of allergens, and occluded for 48 hours; the duplicate right-hand panel was irradiated with 5 J/cm(2) ultraviolet (UV)A. The readings were performed on day (D)2, D4, and D6, in accordance with the guidelines of the ICDRG, and the relevance was evaluated with the COADEX system.

RESULTS

There were a total of 20 photopatch reactions in 15 patients, 95% of which were caused by UV filters, most frequently benzophenone-3 (55%). Eight of the positive reactions (53.3%) appeared on D6.

CONCLUSIONS

UV filters continue to be the most common causes of photoallergic contact dermatitis in our patients. Readings up to D6 (96 h after irradiation) are important to identify delayed positive reactions.

Ketoprofen-induced formation of amino acid photoadducts: possible explanation for photocontact allergy to ketoprofen

Photocontact allergy is a well-known side effect of topical preparations of the nonsteroidal anti-inflammatory drug ketoprofen. Photocontact allergy to ketoprofen appears to induce a large number of photocross allergies to both structurally similar and structurally unrelated compounds. Contact and photocontact allergies are explained by structural modification of skin proteins by the allergen. This complex is recognized by the immune system, which initiates an immune response. We have studied ketoprofen's interaction with amino acids to better understand ketoprofen's photoallergenic ability. Irradiation of ketoprofen and amino acid analogues resulted in four different ketoprofen photodecarboxylation products (6-9) together with a fifth photoproduct (5). Dihydroquinazoline 5 was shown to be a reaction product between the indole moiety of 3-methylindole (Trp analogue) and the primary amine benzylamine (Lys analogue). In presence of air, dihydroquinazoline 5 quickly degrades into stable quinazolinone 12. The corresponding quinazolinone (17) was formed upon irradiation of ketoprofen and the amino acids N-acetyl-l-Trp ethyl ester and l-Lys ethyl ester. The formation of these models of an immunogenic complex starts with the ketoprofen-sensitized formation of singlet oxygen, which reacts with the indole moiety of Trp. The formed intermediate subsequently reacts with the primary amino functionality of Lys, or its analogue, to form a Trp-Lys adduct or a mimic thereof. The formation of a specific immunogenic complex that does not contain the allergen but that can still induce photocontact allergy would explain the large number of photocross allergies with ketoprofen. These allergens do not have to be structurally similar as long as they can generate singlet oxygen. To the best of our knowledge, there is no other suggested explanation for ketoprofen's photoallergenic properties that can account for the observed photocross allergies. The formation of a specific immunogenic complex that does not contain the allergen is a novel hypothesis in the field of contact and photocontact allergy.

A 12-week randomized study of topical therapy with three dosages of ketoprofen in Transfersome® gel (IDEA-033) compared with the ketoprofen-free vehicle (TDT 064), in patients with osteoarthritis of the knee

OBJECTIVE

To evaluate the safety and efficacy of ketoprofen in Transfersome® gel (IDEA-033) in comparison with a ketoprofen-free vehicle (TDT 064) for the treatment of osteoarthritis (OA) of the knee.

METHODS

Patients with knee OA (N = 866) were randomly assigned to receive topical IDEA-033 containing 100, 50, or 25 mg ketoprofen, or TDT 064 twice daily for 12 weeks, in a double-blind trial. The primary efficacy endpoint was the change in the Western Ontario and McMaster Universities (WOMAC®) Osteoarthritis Index pain subscale score. The coprimary efficacy endpoints were the WOMAC function subscale score and the patient global assessment of response to therapy. The secondary endpoints included the numeric pain rating for the first 14 days of treatment and the Outcome Measures in Rheumatology (OMERACT)-Osteoarthritis Research Society International (OARSI) responder rates.

RESULTS

The WOMAC pain scores were reduced by approximately 50% or more in all four groups. The 100 and 50 mg ketoprofen groups, but not the 25 mg group, showed a superior reduction in the WOMAC pain score versus the TDT 064 group (100 mg: -57.4% [P = 0.0383]; 50 mg: -57.1% [P = 0.0204]; and 25 mg: -53.4% [P = 0.3616] versus TDT 064: -49.5%). The superiority of the ketoprofen-containing formulations was not demonstrated for the WOMAC function subscale score, whereas the patient global assessment of 50 mg ketoprofen group, but not the 100 or 25 mg group, was superior to that of the TDT 064 group (P = 0.0283). Responder rates were significantly higher for all the IDEA-033 groups versus the TDT 064 group, but were high in all groups (100 mg: 88.6%; 50 mg: 86.8%; 25 mg: 88.6%; and TDT 064: 77.5%). Dermal reactions were the only relevant drug-related adverse events in all four groups.

CONCLUSION

The 50 and 100 mg ketoprofen doses of IDEA-033 were only marginally superior to TDT 064 for reducing pain associated with knee OA. The study indicates a high treatment response to the topical ketoprofen-free vehicle TDT 064.