Background: Atopic dermatitis (AD) is a common inflammatory dermatosis often accompanied by itching and sleep disturbances. Various treatment options exist, including antihistamines (AHs), even though current clinical recommendations do not mention them. Methods: This prospective exploratory study measured and recorded salivary melatonin at two timepoints (T1 and T2) in three groups of participants: those not treated with AHs, those who discontinued H1-AHs, and those for whom H1-AHs were introduced. Also assessed were disease severity (Scoring Atopic Dermatitis/SCORAD and Eczema Area and Severity Index/EASI), pruritus severity (Peak Pruritus Numeric Rating Scale/NRS), and sleep quality (Pittsburgh Sleep Quality Index/PSQI). Results: The EASI scores were significantly inversely correlated with salivary melatonin levels (p = 0.009) at the first timepoint (T1), but not at the second timepoint (T2). At T2, SCORAD correlated with EASI, NRS, and PSQI (ρ = 0.304–0.842; p ≤ 0.022). EASI correlated with NRS and PSQI (ρ = 0.281–0.453; p ≤ 0.035). Those who discontinued AHs showed increased AD severity indicators (SCORAD, EASI, NRS), whereas participants for whom AHs were introduced showed decreases in the same scores. After adjusting for baseline values, a significant main effect was detected for the treatment group for T2 SCORAD scores (p < 0.001, η² = 0.493). Pairwise comparisons confirmed significant differences among all treatment arms/measures (all p values ≤ 0.023). Changes in melatonin levels between the three groups were not significant when baseline SCORAD values were controlled for. Conclusions: Our exploratory study observed an inverse association between melatonin levels and AD severity at T1, but this was not replicated at T2. This association should be interpreted with caution due to study limitations. Changes in AD severity and pruritus scores following AH initiation or discontinuation were observed, but the study’s non-randomized design and baseline differences between groups preclude a definitive causal inference, and further research on this topic is needed.

Background and Objectives: Although the diagnosis of chronic spontaneous urticaria (CSU) is primarily clinical, detailed history taking and selected laboratory findings are important for patient evaluation and management. Materials and Methods: This explorative prospective study included 41 CSU patients who were followed for 3 months during antihistamine treatment. Saliva and blood samples were collected, and disease-related questionnaires were completed at baseline (T1) and at follow-up (T2). Salivary IL-6 and amylase, serum IL-6, and standard laboratory parameters, including differential blood count, erythrocyte sedimentation rate and/or C-reactive protein (CRP), total IgE, TSH, T4, and anti-TPO antibodies, were measured and compared with disease activity (UAS7), disease control (UCT), and quality of life (DLQI and CU-Q2oL). Results: Salivary IL-6 showed a weak correlation with serum CRP. Neither salivary nor serum IL-6 showed a consistent association with CSU severity, disease control, or quality-of-life scores. Serum IL-6 showed significant correlations with selected inflammatory and thyroid-related parameters. Salivary IL-6 values at baseline (T1) were more frequently increased in patients experiencing a major disease impact on quality of life (CU-Q2oL-measured) than in those with a moderate impact on CU-specific quality of life. Also, higher salivary IL-6 values were expressed in patients with uncontrolled CSU than in well-controlled CSU, as measured by the UCT questionnaire, although without significant difference between these parameters. Conclusions: Salivary IL-6 showed a weak correlation with CRP, but no consistent association with CSU clinical features. Salivary IL-6 is of exploratory interest, but larger controlled studies are needed before any clinical utility can be inferred.

Atopic dermatitis (AD) is a common inflammatory dermatosis often accompanied by itching and sleep disturbances. Various treatment options exist, including antihistamines (AHs) even though current clinical recommendations do not mention them. This prospective study measured and recorded salivary melatonin at two timepoints in three groups of participants: those not treated with AHs, those who discontinued H1-AHs, and those for whom H1-AHs were introduced. Also assessed were disease severity (Scoring Atopic Dermatitis/SCORAD and Eczema Area and Severity Index/EASI), pruritus severity (Peak Pruritus Numeric Rating Scale/NRS), and sleep quality (Pittsburgh Sleep Quality Index/PSQI). Initially, EASI scores significantly negatively, linearly correlated with salivary melatonin levels (p = 0.009). At the second measurement, SCORAD correlated with EASI, NRS, and PSQI (p < 0.001; p = 0.022, and p < 0.001; respectively). EASI correlated with NRS and PSQI (p = 0.003; p < 0.001). In those who discontinued AHs, AD severity indicators significantly increased (SCORAD, EASI, NRS) (p = 0.012; p = 0.012; p = 0.010), while in those for whom AHs were introduced, a significant decrease was observed in SCORAD, EASI, NSR (p = 0.012; p = 0.012; p = 0.010). Those who discontinued AHs showed increased AD severity indicators (SCORAD, EASI, NRS), whereas participants for whom AHs were introduced showed decreases in the same scores. The results support an association between melatonin levels and AD severity, as well as AHs' significant treatment efficacy in AD.