Can chronic spontaneous urticarial produce symptoms of neuropathic pain?

BACKGROUND

Chronic spontaneous urticaria (CSU) is a condition that is associated with recurrent pruritic hives and/or angioedema lasting for more than 6 weeks and is known to affect 1% of the population. Neuropathic pain can be defined as abnormal pain in the peripheral or central nervous system following injury and results from dysfunctions in the peripheral or central nervous system without peripheral nociceptor stimulation. Histamine appears in the pathogenesis of both the CSU and diseases of the neuropathic pain spectrum.

OBJECTIVE

To evaluate the symptoms of neuropathic pain in patients with CSU using scales.

METHOD

Fifty-one patients with CSU and 47 sex- and age-matched healthy controls were included in the study.

RESULTS

The results of the short-form McGill Pain Questionnaire revealed the scores in the sensory and affective domains, Visual Analogue Scale (VAS) scores and pain indices to be significantly higher in the patient group (p < 0.05 for all cases), while the overall pain assessment and sensory assessment based on the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale were also significantly higher in the patient group. Based on the assumption that scores of > 12 indicated neuropathy, 27 (53%) of the patients in the patient group and 8 (17%) in the control group were found to have neuropathy (p < 0.05).

STUDY LIMITATIONS

Cross-sectional study, small patient sample and use of self-reported scales.

CONCLUSION

In addition to itching, patients with CSU should be aware of the potential for the association of neuropathic pain. In this chronic disease that is known to affect the quality of life, using an integrated approach with the patients and identifying accompanying problems are as important as treating the dermatological disorder.

Clarithromycin-treated chronic spontaneous urticaria with the negative regulation of FcεRΙ and MRGPRX2 activation via CD300f

Mast cells (MCs) are main effector cells in chronic spontaneous urticaria (CSU). Both Fc epsilon RI (FcεRΙ)- and MAS-related G coupled receptor-X2 (MRGPRX2)-mediated MC activations affect CSU course. Leukocyte mono-immunoglobulin-like receptor 3 (CD300f) has been shown to regulate FcεRΙ activation. However, no study has verified CD300f is a target to cure CSU. Therefore this study aimed to verify whether clarithromycin (CLA) regulates FcεRΙ- and MRGPRX2-mediated MC activations via CD300f and shows therapeutic effect on CSU. The target of CLA was verification. CLA inhibited FcεRΙ- and MRGPRX2-mediated MC activations were shown in vivo and in vitro. A single-center, self-comparison study was performed, and CLA-treated CSU was investigated in 28 patients who were not sensitive to the third-generation antihistamines. Serum inflammatory mediators in patients before and after CLA administration were analyzed. CLA effectively inhibited type Ι anaphylactic reactions and pseudo-allergic reactions in mice. Moreover, CLA inhibited FcεRΙ- and MRGPRX2-mediated MC signaling pathway activation. Regulatory effects of CLA were decreased significantly after CD300f knockdown. CLA effectively alleviated the symptoms of wheal and itch and reduced serum cytokine levels in patients. CLA negatively regulated FcεRΙ- and MRGPRX2-mediated MC activation via CD300f and showed significant therapeutic effect on CSU.

Response to: Bias in the use of a SSClow/CCR3pos gate to capture basophils in chronic urticaria?

A response to Chirumbolo S, Bjørklund G, and Vella A, Bias in the use of a SSClow/CCR3pos gate to capture basophils in chronic urticaria? Immunobiology, 224(3), 2019, 353-354.

[Inducible urticaria and chronic spontaneous urticaria]

In the recently published 2013 revision of the guidelines of urticaria, chronic urticaria (CU) gathers chronic spontaneous urticaria (CSU) and inducible urticaria (IU), and excludes pseudourticarial rashes with more than 24h-lasting rash or more than 72h-lasting angiœdema. Activity and psychosocial impact of the disease must be measured with validated scores such as Urticaria and Angioedema Activity Scores, Urticaria Control Test, CU-Q2OL, AE-QOL. Although an allergic cause is generaly absent in CU, pathomecanisms remain elusive even since the well-known role of mast cell degranulation and the presence of autoantibodies anti-FcRεI or anti-IgE. Coagulation pathways may be involved, at least as an amplifying phenomenon. Mean duration of CU is 1 to 4 years, but many patients still have symptoms after 10 years, some predictive factors being known as severity, angioedema, a positive autologous serum test, inducible urticaria. Recommended routine diagnosic tests are validated provocation tests for IU (and cryoproteins for cold urticaria), blood cell count and CRP for CSU, since a thorough history and a normal detailed physical examination should avoid unnecessary tests. Management of CU has been improved by the off-label use of increased dosages of second generation anti- H1 antihistamines, but a subsequent therapeutic intensification may be necessary in some cases. Educational program may prevent this intensification. Independent studies evaluating available molecules are needed, along with more fundamental research studies.