Painless Botox: Ethyl chloride spray eases hand and foot discomfort

Key Points

Montreal, Canada – Ethyl chloride spray can relieve discomfort associated with botulinum toxin (Botox, Allergan) injections of the hand and feet, according to the experience of a Canadian dermatologist who uses it regularly in his patients.

"I encourage other dermatologists to use it, because it is cost effective and easy to administer," says Robert Richards, M.D., F.R.C.P.C., a dermatologist affiliated with North York General Hospital/University of Toronto in Toronto, Canada, speaking at the annual meeting of the Canadian Dermatology Association.

Other forms of minimizing discomfort associated with palmar and plantar Botox injections include nerve blocks, vibration, topical anesthetics and various forms of cooling, but according to Dr. Richards, ethyl chloride spray is more effective in relieving the discomfort.

Cost and storage

Gebauer's ethyl chloride medium stream spray has been used for decades to relieve injection discomfort and is readily available from pharmacies or medical suppliers. It costs $35 to $60 per 103.5 ml can and lasts for three to five treatments.

Ethyl chloride spray can be stored at room temperature, but it must not be used near electrodesiccation or other high temperatures, as it is highly flammable.

The ethyl chloride medium stream spray produces a skin temperature of minus 4 degrees Celsius to minus 7 degrees Celsius at a distance of 7 inches.

There is a Gebauer fine stream spray and a mist available, and they are slightly cooler, but their numbing effects are reported not to last as long, Dr. Richards tells Dermatology Times.

Administering ethyl chloride

These products are thought to act by slowing conduction of A delta and C fibers. The gateway blockade theory has also been postulated for their action.

Prior to the procedure, the patient holds an ice pack for two to five minutes, either in the waiting room or while lying supine on the examination table just prior to the procedure.

The palms face upwards at about the patient's head level. Lines or dots are drawn on the palms or soles with a regular pen to indicate the injection sites.

The patient will have previously washed his/her hands or feet with an antiseptic soap.

Dr. Richard's assistant, located at the head of the table, sprays ethyl chloride medium stream spray at a distance of 3 to 7 inches away from the injection site.

"The spray is administered for anywhere from one to four seconds, until the skin begins to blanche or the spray begins to form a liquid pooling on the skin surface," Dr. Richards says.

"The procedure can be performed without an assistant, but more time is required," he adds.

Only two to four sites are injected per spray, as this ensures greater relief from discomfort. Care must be taken not to freeze the skin, as it is difficult to inject and could injure the skin.

One of the pitfalls to avoid is having the needle come into contact with the spray path. If the needle does come into contact with the spray, the Botox solution may freeze.

Dr. Richards typically performs about 40 injections for an average-sized hand. He dilutes Botox 100 units with 4 ml of saline and injects each site with 0.1 cc (2.5 units) of Botox.

The total time to perform the procedure is less than two minutes for each hand. Botox injections of the hands and feet last an average of five to seven months.

Effectiveness

"There are absolutely no side effects that occur with the proper use of ethyl chloride spray," Dr. Richards says.

"It is highly effective. Patients like the results, and they have not complained about any irritation associated with the spray. There are little data available on the use of topical refrigerants such as ethyl chloride spray in patients with Raynaud's, but theoretically, care should be taken," he adds.