Single-dose nonsteroidal anti-inflammatory drugs in horses have no impact on concentrations of cytokines or growth factors in autologous protein solution and platelet-rich plasma.

OBJECTIVE: To determine the effects of a single dose of the NSAIDs phenylbutazone, firocoxib, flunixin meglumine, and ketoprofen on concentrations of growth factors and cytokines in autologous protein solution (APS) and platelet-rich plasma (PRP). ANIMALS: 6 adult university-owned horses. METHODS: For the first phase, 6 horses were randomized to receive ketoprofen (1,000 mg) or flunixin meglumine (500 mg) IV. Blood was obtained and processed for APS (Pro-Stride) and PRP (Restigen) before and 6 hours after administration of NSAIDs. Horses underwent a 2-week washout period, after which the protocol was repeated using a crossover design. For the second phase, following at least a 2-week washout period, the study protocol was repeated with phenylbutazone (1 g) or firocoxib (57 mg) administered orally. Plasma was collected 6 hours after administration for evaluation of drug concentrations, and APS and PRP were analyzed for concentrations of drug, platelets, leukocytes, and several growth factors and cytokines (PDGF, fibroblast growth factor, TGF-ß1, IL-1ß, IL-10, IL-6, IL-8, and tumor necrosis factor-α) before and 6 hours after administration of NSAIDs using immunoassays. RESULTS: There were no significant differences in concentrations of cytokines or growth factors before or after administration of any NSAID. There were significant differences in concentrations of leukocytes and platelets based on both product and time. NSAID concentrations in plasma were not significantly different from concentrations in APS and PRP. CLINICAL RELEVANCE: These results help guide clinicians on the appropriate use of these NSAIDs in conjunction with the processing of APS and PRP, which is unlikely to significantly alter the final product after single-dose administration.

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.

Different Patterns of Response in Hypersensitivity Reactions to Arylpropionic Acid Derivatives.

BACKGROUND: Ibuprofen and other arylpropionic acid derivatives (APs) are among the most consumed nonsteroidal anti-inflammatory drugs worldwide at all age ranges; however, little is known about drug hypersensitivity reactions (DHRs) they induce. OBJECTIVE: To characterize in detail patients reporting DHRs to APs. METHODS: We prospectively evaluated patients with symptoms suggestive of AP-DHRs and analyzed their clinical characteristics, reported reactions, and diagnostic approaches. RESULTS: Six hundred sixty-two patients confirmed as hypersensitive to APs were included: 489 with cross-reactive reactions (CRs) (73.86%) and 173 with selective reactions (SRs) (26.13%). The percentage of subjects reporting reactions to ibuprofen and dexketoprofen was higher in CRs (P = .005 and P = .01, respectively), whereas naproxen and ketoprofen were more frequently involved in SRs (P = .0002 and P = .00001, respectively). The most frequent symptoms induced by ibuprofen, dexketoprofen, and naproxen were isolated angioedema and urticaria, combined or not with angioedema in both CRs and SRs. The result of nasal provocation test with lysine acetylsalicylate was positive in 156 cases (77.14% in patients showing exclusively respiratory symptoms, and in 68.18% of those with both cutaneous and respiratory involvement). To confirm diagnosis, drug provocation test with acetylsalicylic acid was required in 246 CR patients (50.3%), whereas in 28 SR patients (16.18%) drug provocation test with the culprit AP was required. CONCLUSIONS: Skin is the organ most commonly involved in AP-DHRs, with ibuprofen and dexketoprofen inducing most frequently CRs, and naproxen and ketoprofen SRs. More studies are necessary to clarify the underlying mechanism in DHRs induced by APs.

Ketoprofen, lysine and gabapentin co-crystal magnifies synergistic efficacy and tolerability of the constituent drugs: Pre-clinical evidences towards an innovative therapeutic approach for neuroinflammatory pain.

Chronic pain is an enormous public health concern, and its treatment is still an unmet medical need. Starting from data highlighting the promising effects of some nonsteroidal anti-inflammatory drugs in combination with gabapentin in pain treatment, we sought to combine ketoprofen lysine salt (KLS) and gabapentin to obtain an effective multimodal therapeutic approach for chronic pain. Using relevant in vitro models, we first demonstrated that KLS and gabapentin have supra-additive effects in modulating key pathways in neuropathic pain and gastric mucosal damage. To leverage these supra-additive effects, we then chemically combined the two drugs via co-crystallization to yield a new compound, a ternary drug-drug co-crystal of ketoprofen, lysine and gabapentin (KLS-GABA co-crystal). Physicochemical, biodistribution and pharmacokinetic studies showed that within the co-crystal, ketoprofen reaches an increased gastrointestinal solubility and permeability, as well as a higher systemic exposure in vivo compared to KLS alone or in combination with gabapentin, while both the constituent drugs have increased central nervous system permeation. These unique characteristics led to striking, synergistic anti-nociceptive and anti-inflammatory effects of KLS-GABA co-crystal, as well as significantly reduced spinal neuroinflammation, in translational inflammatory and neuropathic pain rat models, suggesting that the synergistic therapeutic effects of the constituent drugs are further boosted by the co-crystallization. Notably, while strengthening the therapeutic effects of ketoprofen, KLS-GABA co-crystal showed remarkable gastrointestinal tolerability in both inflammatory and chronic neuropathic pain rat models. In conclusion, these results allow us to propose KLS-GABA co-crystal as a new drug candidate with high potential clinical benefit-to-risk ratio for chronic pain treatment.

Bizarre Cutaneous Ulcers due to Self-Administered Intravenous Dexketoprofen Trometamol.

Systemic non-steroidal anti-inflammatory drug use may result in various cutaneous complications including maculopapular rash, fixed drug eruption, urticaria, and angioedema most frequently. However extensive cutaneous ulcers in relation to intravenous dexketoprofen trometamol use has not been identified before although cutaneous ulcers have been described in association with several opioids. Herein, we would like to present a 27-year-old male with a 1-year history of progressive deep cutaneous ulcers due to long term abusive intravenous use of dexketoprofen trometamol.

Effect of CYP2C9, PTGS-1 and PTGS-2 gene polymorphisms on the efficiency and safety of postoperative analgesia with ketoprofen.

OBJECTIVES: Patients undergoing cardiac surgery develop post-sternotomy pain syndrome. The aim of this study was evaluation of the influence of CYP2C9, PTGS-1 and PTGS-2 genes polymorphisms on the efficacy and safety of postoperative analgesia with ketoprofen in patients with coronary artery disease after cardiac surgery. METHODS: The study included 90 patients undergoing cardiac surgery. A real-time polymerase chain reaction was used for the detection of single nucleotide polymorphisms (SNP). Pain intensity was measured by the Numeric Rating Scale (NRS). Dyspeptic symptoms were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS). Acute kidney injury (AKI) was determined by Kidney Disease Improving Global Outcomes criteria. RESULTS: Pain intensity by the NRS score was significantly higher in patients with CYP2C9*3 АA genotype compared to АC genotype: 7 [1,10] and 6 [2,7] (p=0.003); 7 [1,10] and 6 [2,7] (p=0.04); 6 [0; 10] and 5 [2,6] (p=0.04); 5 [0; 8] and 3 [0; 8] (p=0.02), on days 1, 2, 3 and 5 in the postoperative period, respectively. GSRS score was higher in patients with CYP2C9*2 CT genotype compared to CС genotype: 19 [15; 42] and 18 [15,36] (p=0.04), respectively. There were no significant differences in the pain intensity, dyspepsia severity and AKI frequency in patients with homozygous and heterozygous genotypes for PTGS-1 rs10306135, PTGS-1 rs12353214, PTGS-2 rs20417. CONCLUSIONS: CYP2C9*3 and CYP2C9*2 gene polymorphisms may affect efficacy and safety of postoperative analgesia with ketoprofen in patients with coronary artery disease after cardiac surgery.

Preemptive analgesia for hemorrhoidectomy: study protocol for a prospective, randomized, double-blind trial.

BACKGROUND: Hemorrhoidectomy is associated with intense postoperative pain that requires multimodal analgesia. It includes nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and local anesthetics to reach adequate pain control. There are data in literature preemptive analgesia could decrease postoperative pain after hemorrhoidectomy. The aim of this study is to assess the efficacy of preemptive analgesia with ketoprofen 100 mg 2 h before procedure per os with spinal anesthesia to decrease postoperative pain according to visual analog scale and to reduce the opioids and other analgesics consumption. METHODS: Patients of our clinic who meet the following inclusion criteria are included: hemorrhoids grade III-IV and the planned Milligan-Morgan hemorrhoidectomy. After signing the consent all participants are randomly divided into 2 groups: the first one gets a tablet with 100 mg ketoprofen, the second one gets a tablet containing starch per os 2 h before surgery (72 participants per arm). Patients of both arms receive spinal anesthesia and undergo open hemorrhoidectomy. Following the procedure the primary and secondary outcomes are evaluated: opioid administration intake, the pain at rest and during defecation, duration, and frequency of other analgesics intake, readmission rate, overall quality of life, time from the procedure to returning to work, and the complications rate. DISCUSSION: Multimodality pain management has been shown to improve pain control and decrease opioid intake in patients after hemorrhoidectomy in several studies. Gabapentin can be considered as an alternative approach to pain control as NSAIDs have limitative adverse effects. Systemic admission of ketorolac with local anesthetics also showed significant efficacy in patients undergoing anorectal surgery. We hope to prove the efficacy of multimodal analgesia including preemptive one for patients undergoing excisional hemorrhoidectomy that will help to hold postoperative pain levels no more than 3-4 points on VAS with minimal consumption of opioid analgesics. TRIAL REGISTRATION: ClinicalTrial.gov NCT04361695 . Registered on April 24, 2020, version 1.0.

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 components present in a magazine cover are responsible for a patient's skin reaction, to determine the primary sensitizer, and precisely diagnose ACD and PACD. METHODS: After initial photo-patch 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 photo-patch tests were performed. RESULTS: The first photo-patch 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 photo-patch tests confirmed PACD to 1-HCPK and to benzophenone, and photo-aggravated ACD to 4-MBP. The primary sensitizer was ketoprofen. CONCLUSIONS: Benzophenones are present in a wide variety of products, without always being listed on the packaging. Patients previously sensitized 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.

Intravenous lidocaine vs. NSAIDs for migraine attack in the ED: a prospective, randomized, double-blind study.

PURPOSE: Although different forms of lidocaine are used for migraine attack headaches, the effect of intravenous lidocaine is still limited. This study aimed to investigate the effects of intravenous lidocaine infusion for the treatment of migraine attack headaches. METHODS: A hundred patients with migraine attacks, aged between 18 and 65, were randomly divided into two groups. The lidocaine group (n = 50) received a 1.5 mg/kg lidocaine bolus and a 1 mg/kg infusion (first 30 min), followed by a 0.5 mg/kg infusion for a further 30 min intravenously. The non-steroidal anti-inflammatory drug (NSAID) group (n = 50) received 50 mg dexketoprofen trometamol and saline at the same volume as the lidocaine at the same time intervals intravenously. The Visual Analog Scale (VAS) pain scores, additional analgesia requirement, side effects, and revisits to the emergency department were recorded. RESULTS: The VAS score was significantly lower in the lidocaine group than in the NSAID group for the first 20th and 30th minutes (p = 0.014 and p = 0.024, respectively). There was no difference between the VAS scores for the remaining evaluation times (p > 0.05). In terms of secondary outcomes, rescue medication requirement was not different between the two groups at both the 60th and 90th minutes (p > 0.05). However, the number of patients revisiting ED within 48-72 h was statistically less in the lidocaine group than in the NSAID group (1/50 vs. 8/50; p = 0.031). CONCLUSION: Intravenous lidocaine may be an alternative treatment method for patients with migraine attack headaches in the emergency department.

Ketoprofen-induced Photoallergic Reaction.

Dear Editor, Photoallergic reactions are classic T-cell-mediated or delayed-type hypersensitivity reactions of the skin in response to a photoallergen (or a cross-reacting chemical) to which a subject was sensitized in the past (1). The immune system recognizes the changes caused by ultraviolet (UV) radiation; it produces antibodies and causes inflammation of the skin in the exposed areas (2). Common photoallergic drugs and ingredients are included in some sunscreens, aftershave lotions, antimicrobials (especially sulfonamides), non-steroidal anti-inflammatory drugs (NSAIDs), diuretics, anticonvulsants, chemotherapy drugs, fragrances, and other hygiene products (1,3,4). A 64-year-old female patient was admitted to the Department of Dermatology and Venereology with erythema and underlining edema on her left foot (Figure 1). A few weeks earlier, the patient had had a fracture of the metatarsal bones and since then she had been taking NSAIDs systemically every day to suppress pain. Five days before being admitted to our Department, the patient started applying 2.5% ketoprofen gel to her left foot twice daily and was frequently exposed to the sun. For the last twenty years, the patient had been struggling with chronic back pain and was frequently taking different NSAIDs (ibuprofen, diclofenac, etc.). The patient also suffered from essential hypertension and was regularly taking ramipril. She was advised to discontinue ketoprofen application, avoid sunlight, and apply betamethasone cream twice daily for 7 days, which lead to complete resolution of the skin lesions in a few weeks. Two months later, we performed patch and photopatch tests to baseline series and topical ketoprofen. Only the irradiated side of the body where ketoprofen-containing gel was applied showed positive reaction to ketoprofen. Photoallergic reactions manifest as eczematous, pruritic lesions, which may spread to involve other areas of the skin that were not previously exposed to the sun (4). Ketoprofen is a nonsteroidal anti-inflammatory drug composed of a benzoylphenyl propionic acid that is commonly used both topically and systemically for the treatment of musculoskeletal diseases because of its analgesic and anti-inflammatory effects and low toxicity, but it is one of the most frequent photoallergens (1,5,6). Ketoprofen-induced photosensitivity reactions usually present as photoallergic dermatitis characterized as acute dermatitis with edema, erythema, papulovesicles, blisters, or erythema exsudativum multiforme-like lesions at the application site 1 week to 1 month after the initiation of use (7). Depending on the frequency and intensity of sun exposure, ketoprofen photodermatitis may continue or reoccur up to 1 to 14 years after discontinuing the medication (6,8). Moreover, ketoprofen contaminates clothing, shoes, and bandages, and some cases of photoallergy relapses have been reported that were induced by ketoprofen-contaminated objects after they were used again in the presence of UV radiation (5,6). Due to their similar biochemical structure, patients with ketoprofen photoallergy should avoid using some drugs such as some NSAIDs (suprofen, tiaprofenic acid), antilipidemic agent (fenofibrate) and sunscreens based on benzophenones (6,9). Physicians and pharmacists should advise patients of the potential risks when topical NSAIDs are applied on the photoexposed skin.

Comparison of the Efficacy and Safety of Ketoprofen Plaster and Diclofenac Plaster for Osteoarthritis-Related Knee Pain: A Multicenter, Randomized, Active-Controlled, Open-Label, Parallel-Group, Phase III Clinical Trial.

PURPOSE: To compare the efficacy and safety of ketoprofen plasters and diclofenac plasters after 3 weeks of administration in patients with osteoarthritis-related knee pain. METHODS: This multicenter, randomized, active-controlled, open-label, parallel-group, noninferiority phase III study randomized 236 adults with osteoarthritis-related knee pain for 3 weeks with ketoprofen plaster 30 mg twice daily (n = 118) or diclofenac plaster 15 mg once daily (n = 118). The primary efficacy end point was the mean change from baseline to week 3 in the mean knee pain intensity score during walking, as measured by a 100-mm visual analog scale with a predefined noninferiority margin of 10.0 mm. Secondary end points included changes in knee pain intensity score during walking (weeks 1 and 2) and at rest (weeks 1, 2, and 3), Knee Injury and Osteoarthritis Outcome Score, Patient Global Impression of Improvement scale assessments, and frequency of rescue medication use after 2 and 3 weeks of treatment. FINDINGS: A total of 223 patients (115 in the ketoprofen group and 108 in the diclofenac group) were included in the per-protocol analysis. After 3 weeks of treatment, the least squares mean change from baseline in knee pain intensity scores during walking was -35.9 (95% CI, -39.7 to -32.2) in the ketoprofen group and -31.7 (95% CI, -35.5 to -27.9) in the diclofenac group, with noninferiority found (least squares mean difference, -4.2; 95% CI, -9.6 to 1.1). Ketoprofen significantly (P < 0.05) reduced the pain intensity score at rest after 2 and 3 weeks of treatment compared with diclofenac. No statistically significant difference was found between the groups in terms of changes in pain intensity score during walking at weeks 1, 2, and 3. The mean Patient Global Impression of Improvement score was statistically significant (P < 0.001) in favor of ketoprofen after 2 and 3 weeks of treatment. In addition, the Knee Injury and Osteoarthritis Outcome Score improved in both groups, and no statistically significant difference was found between the groups in terms of frequency of rescue medication use. The overall adverse event profile of the groups was similar, and no difference was found in skin reaction rates between the 2 groups. IMPLICATIONS: Ketoprofen plasters can be effectively and safely administered to patients with osteoarthritis-related knee pain.

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.

SAFETY OF MULTIPLE-DOSE INTRAMUSCULAR KETOPROFEN TREATMENT IN LOGGERHEAD TURTLES (CARETTA CARETTA).

Sea turtles are frequently presented for rehabilitation with injuries for which analgesic treatment is warranted. Ketoprofen is a nonsteroidal anti-inflammatory drug (NSAID) widely used in clinical veterinary medicine for musculoskeletal pain relief. Pharmacokinetics of 2 mg/kg IM have been studied in loggerhead sea turtles (Caretta caretta) as a single and a repeated dose q24hr for 3 days. Safety of longer term administration has not been performed, however, and NSAID use carries a risk of potential complications, including gastrointestinal ulceration, kidney damage, and bleeding. The objective of the current study was to determine the effects of a 5-day course of ketoprofen on thromboelastography (TEG) and hematological (including thrombocytes) and plasma biochemical analytes in loggerheads. A secondary objective was to determine 24-hr trough concentrations of ketoprofen after 5 days of treatment. Eight loggerheads were treated with ketoprofen 2 mg/kg IM q24hr for 5 days, and TEG, hematology, and plasma biochemistry panels were performed before and at the conclusion of treatment. Eight controls were treated with an equivalent volume of saline intramuscularly. Virtually no changes were detected before and after treatment or between treatment and control groups in any of the 24 endpoints evaluated, and marginal differences were not considered clinically relevant. Plasma ketoprofen concentrations after 5 days of treatment indicated no accumulation over that duration. Ketoprofen at 2 mg/kg IM q24hr for up to 5 days in loggerheads appears safe with respect to blood clotting and blood data, although other potential effects were not evaluated.

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.

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.

Usefulness of Patch Testing With Patient's Own Products in the Diagnosis of Allergic Contact Dermatitis.

BACKGROUND: The usefulness of using patient's own products in patch tests for the diagnosis of allergic contact eczema is well known. However, most of the literature is based on case series published decades ago, and they are focused on cosmetics and fragrances. OBJECTIVE: The aim of the study was to evaluate the usefulness of using patient's own products in patch tests for the diagnosis of contact eczema in a contact dermatitis unit, describing the most frequently positive own products, as well as the most frequently responsible allergens. METHODS: In a 17-year period, 3514 patients were patch tested in our department. In 2429 patients, patch testing with the patients' own products was performed. RESULTS: We found that 363 patients (10.33%) reacted to their own products. In 131 cases (3.81%), reacting to their own product was the only clue for detecting the responsible allergen for allergic contact eczema. Most reactions were found for topical medications, moisturizers, and adhesives. Fragrance mix I, methylchloroisothiazolinone/methylisothiazolinone, ketoprofen, and colophony were found to be the allergens most often responsible. CONCLUSIONS: It is essential to include patient's own products in the study of allergic contact eczema to make a correct diagnosis. In our series, 3.81% of the patients would not have been correctly diagnosed if their own products had not been included in patch tests.