Scalp platelet-rich plasma (PRP), a globally increasing in-office procedure to treat hair loss, uses two delivery methods to hair follicles. The methods are direct needle injection to the scalp or administration with microneedling of the scalp using a needling device. Both methods generate pain and discomfort during the procedure, and most patients require anesthesia to ease the discomfort.

In both the forms (contact and noncontact), skin cooling is a vital treatment modality; for example, scalp cooling minimizes chemotherapy-induced alopecia and may also serve as a noninvasive pain control method (cryoanesthesia and cryoanalgesia) in procedural dermatology and laser skin treatments. A recent study described a simple office-based solution to alleviate the discomfort of PRP and a microneedling procedure by cooling the scalp to achieve cryoanesthesia.

In this method, the patient has to wear a frozen hypothermic scalp cap (Elasto-gel) maintained at <10°C to cool the scalp for 30 minutes before the procedure. After removing the cap, the injection is immediately started. 

Wetting the hair with water or numbing cream before applying the cold cap boosts hair conductivity, leading to a faster scalp temperature reduction and analgesia. We can easily disinfect the cap after the procedure.

This technique is useful when performing scalp PRP as it is simple yet effective. Furthermore, it also helps to decrease local anesthesia risks and discomfort.

Source: Alsalhi W, Tosti A. Cryo-Cap anesthesia to minimize scalp discomfort during platelet-rich plasma injection. Skin Appendage Disord. 2022;8(5):406.