Salivary Melatonin Levels in Comparison with Disease Features and Antihistamine Use: Prospective Follow-Up of Atopic Dermatitis Patients.

EASI scores were significantly inversely correlated with salivary melatonin levels at the first timepoint (T1) but not at the second timepoint (T2).

• The T1 association had p = 0.009.
• The association was not replicated at T2.
• The authors say the association should be interpreted with caution because of study limitations.

At T2, atopic dermatitis severity scores correlated with pruritus and sleep quality measures.

• 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).

Participants who discontinued antihistamines showed increased AD severity and pruritus indicators, while those for whom antihistamines were introduced showed decreases.

• The indicators that increased after discontinuation were SCORAD, EASI, and NRS.
• The same scores decreased in participants for whom H1-AHs were introduced.
• The study had three groups: no AH treatment, AH discontinuation, and AH introduction.

After adjusting for baseline values, treatment group had a significant main effect on T2 SCORAD scores, with significant pairwise differences among all treatment arms.

• Main effect of treatment group on T2 SCORAD: p < 0.001, η2 = 0.493.
• Pairwise comparisons confirmed significant differences among all treatment arms/measures (all p ≤ 0.023).

Changes in salivary melatonin levels did not differ significantly between the three groups when baseline SCORAD values were controlled for.

• Salivary melatonin was measured at two timepoints (T1 and T2).
• The groups were no AH, discontinued H1-AH, and introduced H1-AH.

The study's design limits causal inference about antihistamine effects.

• The study was prospective and exploratory, and non-randomized.
• Baseline differences between groups were present.
• The authors state that further research is needed.