Assessment of the impact of sex in intensity, skin flares and central processing of histaminergic itch-A pilot study.

Itch is the commonest skin-related symptom, and sex differences are increasingly recognised as important determinants in stratified medicine, but only little is known about sex differences in itch. Questionnaire-based studies indicated that women perceive itch as more intensive and bothersome in comparison with men. However, data of studies using standardised itch models to objectify sex differences are scarce and inconsistent. To determine sex differences in intensity, skin flares and central processing of histaminergic itch, we compared 15 female and 15 male healthy subjects in a double-blinded, within-subject, placebo-controlled study using a histamine skin prick itch model (histamine 1% applied onto the volar forearm) and functional MRI. We found trends in higher mean itch intensity (0.58 VAS, CI 95% 0.004-1.19, P = .056) and maximum itch intensity (men 3.93 VAS ± 0.39 SD at 3 minutes, women 4.73 VAS ± 0.31 SD at 4 minutes, P = .073) in women paralleled by a trend in a stronger positive correlation between itch intensity and blood oxygen level-dependent (BOLD) activity in brain structures identified during itch in comparison with men (rs in women: .46, P = .08, rs in men: .07, P = .79). The erythema and wheal following histamine skin pricking were (non-significantly) larger in men, indicating that higher mean itch intensities on the right volar forearm in women may not be explained by more intense flares. The comparison of the activation patterns between the sexes revealed increased activity in men compared to women in the left middle temporal gyrus (temporooccipital part)/lateral occipital cortex. Thus, our findings indicate that histaminergic itch perception and central itch processing differ between the sexes under standardised conditions.

Relevance of grade 1 gray-scale ultrasound findings in wrists and small joints to the assessment of subclinical synovitis in rheumatoid arthritis.

OBJECTIVE: To investigate the clinical relevance of grade 1 findings on gray-scale ultrasound (GSUS) of the joints in patients with rheumatoid arthritis (RA). METHODS: We examined the wrists and small joints of 100 patients with early or established RA and 30 healthy controls, using GSUS and power Doppler ultrasound (PDUS). Independent clinical assessment of all joints for tenderness and swelling according to the European League Against Rheumatism examination technique was performed. Joints with grade 1 findings on GSUS were identified, and associations with swelling, pain, and findings on PDUS were assessed. Grade 1 findings on GSUS in patients with early RA were reassessed after 6 months of antirheumatic treatment. RESULTS: Grade 1 results represented the majority of all GSUS findings in patients with RA and were also frequently recorded in healthy controls. Grade 1 GSUS findings were not associated with tenderness, swelling, or positive results on PDUS. In comparison to joints with grade 2 and grade 3 findings on GSUS, joints with grade 1 findings were less likely to respond to treatment. CONCLUSION: The present results indicate that grade 1 findings on GSUS have limited clinical relevance.