Hair cosmetics are in fashion. Numerous products are commonly used in combination. Frequent allergens are present in hair cosmetics, which, added to almost daily use, increase the risk of sensitization. Familiarity with the clinical distribution of the eczematous rash is necessary to seriously consider patch testing. There are haptens on the market, although not all of them. It is necessary to know how to patch your own products. When avoidance of the allergen cannot be possible, new treatments are being evaluated to combat allergic contact dermatitis, mainly of the occupational type. In this manuscript, a complete and practical review of the main allergens and contact sources of hair cosmetic origin has been carried out.

Introduction. Psoriatic disease (PsD), encompassing psoriasis, psoriatic arthritis, inflammatory bowel disease, and uveitis, presents a significant burden due to its chronic and diverse inflammatory nature, affecting various clinical domains including skin, joints, and internal organs. Psoriasis, affecting up to 3% of the global population, not only poses physical challenges but also profoundly impacts patients' psychological well-being, ranking among the most debilitating chronic conditions. Furthermore, PsD exhibits a spectrum of manifestations ranging from skin lesions like plaque psoriasis to systemic complications such as cardiovascular comorbidities, necessitating comprehensive assessment and management strategies. The increasing understanding of the aetiopathogenic mechanisms of these immune-mediated diseases and of the proinflammatory intracellular signalling pathways involved in Psoriatic disease (PsD) has facilitated the identification and development of new small molecules capable of inhibiting JAK proteins, emerging as effective treatment options for rheumatic and dermatological manifestations JAK inhibitors act rapidly, within a few days, with a striking beneficial class effect on pain. The oral formulation they share makes them a well-tolerated class of drugs, with a clear advantage over FAME in terms of convenience of administration, improving therapeutic compliance. Material and method. This observational, retrospective study conducted in a single-centre dermatology-rheumatology consultation of a second-level hospital in Granada, Spain, focused on patients diagnosed with Psoriatic Arthritis (PsA) over the last two years, who initiated treatment with Tofacitinib or Upadacitinib due to DMARD failure, excluding those with major contraindications to JAK inhibitors. Results: This study analyzed data from 32 patients diagnosed with Psoriatic Arthritis (PsA), focusing on their demographics, disease characteristics, and treatment history. The majority of patients (75%) initiated treatment with Tofacitinib, while the remainder started with Upadacitinib. The mean age of the patients differed between the two treatment groups. All patients met the CASPAR criteria for PsA diagnosis, with predominantly peripheral joint involvement. The average time from PsA diagnosis to initiation of JAKinhib treatment was 6.5 years, slightly longer for Upadacitinib users. Most patients presented with cutaneous psoriasis, and a minority exhibited radiographic erosions. Before JAKinhib therapy, all patients had previously received DMARDs. A subset of patients received concomitant DMARD therapy, predominantly methotrexate. Additionally, a proportion of patients were on low-dose corticosteroids. Baseline CRP and ESR levels were indicative of systemic inflammation. Disease activity measures at baseline indicated moderate disease activity, with a substantial proportion of patients having mild psoriasis involvement. Upadacitinib recipients with psoriasis primarily exhibited mild involvement. This study provides valuable insights into the characteristics and treatment patterns of PsA patients initiating JAKinhib therapy. Discusion. In this study, the efficacy, safety, and real-world outcomes of Janus kinase inhibitors (JAKinhibs) in the treatment of Psoriatic Arthritis (PsA) were assessed and compared with findings from pivotal randomized controlled trials (RCTs). Both Tofacitinib and Upadacitinib demonstrated significant efficacy in PsA patients refractory to DMARDs and TNF inhibitors, with rapid improvement in joint and skin activity indices. Although patients in this cohort exhibited younger age, higher female prevalence, and shorter disease duration compared to those in RCTs, treatment responses were comparable or even superior. Notably, despite fewer concurrent DMARDs and a higher proportion of patients receiving monotherapy, JAKinhibs maintained a favorable safety profile, with a low frequency of mild adverse events leading to treatment discontinuation. These findings emphasize the robust efficacy and tolerability of JAKinhibs in real-world clinical settings, supporting their role as effective therapeutic options for PsA patients.