Oral cyclosporine effective drug in decreasing episodes and intensity of cholinergic itch

Cyclosporine effective in cholinergic itch- IDOJ

Cholinergic itch can be transient, mild, and self‑resolving but in some patients it can interfere with the daily activities due to episodes of intense pruritus which can even force a patient to avoid the triggers (e.g., exercise, warm clothing, field works). It is usually relieved by cooling the skin or in some cases taking the clothes off, which can be considerably embarrassing.

Various mechanisms have been proposed which can explain the development of cholinergic itch and cholinergic urticaria symptom complex:

• Acetylcholine can act as endogenous algesiogenic in human skin especially in cholinergic urticaria and aquagenic pruritus.
• Histamine also acts as an itch mediator, and its release can be stimulated by sweat‑induced acetylcholine.
• Xerosis induces sweat duct obstruction in winters, resulting in inflammatory substances contained in sweat being refluxed into the dermis. Sweat materials contain numerous pruritogenic substances such as a renin‑like substance, immunoglobulin E, secretory immunoglobulin A, and cytokines including interleukin 1/8/ß which can induce local inflammatory reactions.
• Imbalance in cutaneous expression of several neuropeptides like substance P, vasoactive intestinal peptide, and neuropeptide Y is believed to be involved in the itch production in several skin diseases.

Results

Of the 20 patients, 19 were males and 1 was female. Mean age of the patients was 15.95 years. Mean age of the onset of disease was 19.5 years. Mean duration of the disease was 13.3 months. Cholinergic itch occurred more during winters (65%). Eight (40%) patients had a history of atopic diathesis. Mean NRS before

initiating treatment was 7.8 which decreased to 0.3 at the end of the second week. Eighteen patients (90%) reported the absence of any episode of cholinergic itch at the end of the first week of initiating cyclosporine therapy. The other two patients continued to develop cholinergic itch during the first 2 weeks with a significant decline in NRS score (initial mean NRS = 8.5 to NRS = 3). No episode of cholinergic itch occurred in any of the included patients after 2 weeks of starting cyclosporine therapy, even when the dose was tapered to as low as 50 mg/day over the period of 14 weeks. No post‑treatment follow‑up was performed.

Antihistamine drugs are considered as first‑line treatment in cholinergic urticaria though not always effective. Cyclosporine is known to produce anti‑inflammatory and neuromodulatory actions. Apart from anti‑inflammatory action, it may also have anti‑pruritic activity produced through neuromodulation by suppressing "pruritogenic cytokines" and by directly acting on cutaneous nerve endings, which leads to decreased levels of neuropeptide substance P, nerve growth factor, and neurotrophin‑3. It also decreases itch via interleukin‑31RA inhibition and decreased TRPV1 and NKR1 gene expression.

To conclude oral cyclosporine appears to be a very effective drug in decreasing the number of episodes and intensity of cholinergic itch within a very short duration of time (5–7 days). It can be considered as a short‑duration alternative therapeutic option in patients of refractory severe cholinergic itch.

References-

1. Sehgal S, Arora V, Gupta L, Khare AK, Vyas K, Mittal A. Cyclosporine in cholinergic itch. Indian Dermatol Online J 2022;13:234-6.