Swift is a revolutionary microwave technology that can be used to treat multiple dermatologic conditions of the skin. It was designed and launched in the United Kingdom and became available to practitioners in the United States in January of 2019. Swift was first developed for the treatment of stubborn plantar warts. However, current applications for the device have expanded to treating all warts, molluscum (viral infection), and corns. Future clinical applications include treating actinic keratoses (precancerous lesions), fungal nail infections and superficial skin cancers. The Swift device uses low-dose, non-ablative microwave energy to heat the tissue to 45 degrees Celsius. This rapid and sudden rise in heat stresses the skin cells and causes a tissue reaction. The advantage of treating with the Swift device is that there is no post-procedure pain, no blisters, no band-aids, no pigment changes or scarring and no at-home treatment. There is minimal pain during the treatment and the pain subsides immediately. Swift treatments are safe to use on the face and genitals, on children, skin of color, and on pregnant or breastfeeding women.
Warts & Molluscum
Warts are caused by the human papillomavirus (HPV). This virus is very common and has more than 150 types. Different types of HPV cause different infections, such as common warts, flat warts, plantar warts, and genital warts. Some HPV types are associated with cervical cancer and oral cancer. The wart virus is spread through physical contact with another person or object. Eventually our immune system will recognize the presence of the wart virus and clear the infection. However, this process can take several years and during that time, the warts may spread and become more bothersome. Current wart treatments are aimed at getting our immune system to recognize the presence of the wart virus and to mount an immune response to clear the infection. There are three main ways to get the immune system to recognize a viral infection; they are by either causing injury to the skin (destructive), causing a rash (allergic contact or irritant contact) to the area, or by injecting a foreign antigen into the wart. Destructive methods include liquid nitrogen (cryotherapy), cantharidin, electrosurgery and curettage, excision, laser, chemical peels (salicylic acid, glycolic acid, tretinoin) and bleomycin injection. Topical therapy involves applying a cream or solution to the wart(s) to create either an irritant contact or an allergic contact rash. There are several topical medications including diphencyprone (DCP), squaric acid, 5-fluorouracil, imiquimod, podophyllotoxin, sinecatechins, cidofovir, and bensal compound. Injection a foreign antigen into the wart, such as Candida albicans (a yeast), measles, mumps and rubella (MMR), trichophyton (fungus), and the tuberculin antigens (PPD or BCG) is presumed to trigger an immune response within the wart to fight the infection.
The frustration with our current therapies is that they are not very effective, they often require multiple visits to the clinic, can be painful and often have a high recurrence rate. Along came Swift, giving us an effective option like none other!
Swift was first developed for the treatment of stubborn plantar warts. Studies revealed that treatment with Swift for stubborn plantar warts was 85% effective after 2 or 3 treatments and had a recurrence rate of less than one percent. It was discovered that when the skin tissue undergoes the rapid and sudden rise of heat from the microwaves, it stresses the skin cell causing it to release “heat shock protein (HSP) 70”. HSP 70 is a signal that alerts the immune system to a viral infection, creating an immune cascade that produces specific killer T cells to target and destroy the skin cells infected with the virus. The microwaves that are emitted from the device can penetrate deeper into the skin than any other current wart treatment available today. Because Swift works by causing a regional immune response in the surrounding tissue, it is not necessary to treat each individual wart lesion. Swift is also effective in the treatment of molluscum, which is another type of viral skin infection. Treatment is recommended every 4 weeks for 2-3 sessions. Patients are then seen back in 3 months for a follow-up evaluation.
A corn, also known as a clavus, is an uncomfortable, thickened skin lesion that is a result of repeated mechanical trauma due to friction and/or pressure forces. A corn is different from a callus. A corn is a focal area of hyperkeratosis (thickened skin) presenting with a white core when debrided. Contributing factors in the development of a corn are ill-fitting footwear, the presence of bony prominences, certain physical activities, foot deformity, and loss of fat pads with age. Corns are most common on the feet, including the soles, dorsum of the toes and in between the toes. The formation of a corn is a protective body reaction that produces an excess of the horny epithelial layer to prevent skin ulceration. The problem that results from the body protecting itself by creating this horny proliferation, is that it creates pain when walking. Therapies for corn(s) include paring of the lesion, topical keratolytic medications (salicylic acid), ablative laser therapy, surgical excision, proper footwear, orthotics and soft cushions.
Swift has been shown to improve the pain associated with corns, and in some cases have led to complete resolution of the corns. The lesion is pared with a curette prior to treatment. It is recommended to have 3 treatments every 4 weeks. It is reported that after the first treatment, the pain associated with the corn has improved significantly. After the 3rd treatment, a single maintenance treatment is needed once the pain has returned, which is between 6-9 months. Daily maintenance treatment with moisturizers, corn pads, paring the corn after bathing with a pumice stone and utilizing orthotics (if applicable) can help lengthen the time between treatments. Resolution of corns with the Swift device is thought to be due to the presence of the wart virus that has been found in up to 50% of corns. The reason for the pain relief associated with treating corns with the Swift device is unknown, but thought to be due to two possible mechanisms. The first is through desensitization of nerves in the treatment area. If the nerves are not firing, there is little to no pain. The second proposed mechanism of action is the stimulation of collagen production. It is well known that microwaves do stimulate collagen production which can help reverse the body’s natural response to mechanical pressure over bony prominences due to loss of collagen and fat pads as we age.
At Central Minnesota Dermatology we look forward to offering you future treatment applications for the Swift device. The dermatologic conditions currently in clinical trial include actinic keratoses, fungal nail infections, and superficial skin cancers.