Therapies for Alopecia—Topical and IL corticosteroids are the first-line therapies for localized AA in patients with less than 50% scalp involvement. Triamcinolone acetonide generally is the IL steroid of choice because it is widely available and less atrophogenic than other steroids. Unlike topicals, ILTA bypasses the epidermis when injected, achieving direct access to the HF.14
High-quality controlled studies regarding the use of ILTA in AA are scarce. A meta-analysis concluded that 5 mg/mL and 10 mg/mL of ILTA diluted in NS were equally effective (80.9% [P<.05] vs 76.4% [P<.005], respectively). Concentrations of less than 5 mg/mL of ILTA resulted in lower rates of hair regrowth (62.3%; P=.04).15 The role of diluents other than NS has not been studied.
Benefits of Epinephrine in ILTA Therapy—The role of epinephrine 1:100,000 is to decrease the rate of clearance of triamcinolone acetonide from the HF, allowing for a better therapeutic effect. Laser Doppler blood flowmeter studies have shown that epinephrine 1:100,000 injected in the scalp causes vasoconstriction, thereby decreasing the blood flow rate of clearance of other substances in the same solution.16 Also, a more gradual systemic absorption is achieved, decreasing systemic side effects such as osteoporosis.17
Another potential benefit of epinephrine has been suggested in animal studies that demonstrate the important role of the sympathetic nervous system in HF growth. In a mouse study, chemical sympathectomy led to diminished norepinephrine levels in the skin, accompanied by a decreased keratinocyte proliferation and hair growth. Conversely, norepinephrine was found to promote HF growth in an organotypic skin culture model.18 Topically applied isoproterenol, a panadrenergic receptor agonist, accelerated HF growth in an organotypic skin culture. It also has been shown that external light and temperature changes stimulate hair growth via the sympathetic nervous system, promoting anagen HF growth in cultured skin explants, further linking HF activity with sympathetic nerve activity.19
In our experience, cases of AA that at first failed ILTA 5 mg/mL in NS have been successfully treated with 2.5 mg/mL ILTA in 1% lidocaine and epinephrine 1:100,000. One such case was alopecia totalis, though we do not have high-quality photographs to present for this report. The 2 cases presented here are the ones with the best photographs to demonstrate our outcomes. Both were treated with 2.5 mg/mL ILTA in 1% lidocaine and epinephrine 1:100,000 administered using a 0.5-in long 30-gauge needle, with 0.05 to 0.1 mL per injection approximately 0.51-cm apart. The treatment intervals were 4 weeks, with a maximal dose of 20 mg per session. In addition to the 2 cases reported here, the Table includes 2 other patients in our practice who were successfully treated with this novel regimen.
Prior to adopting this combination regimen, our standard therapy for AA was 5 mg/mL ILTA buffered with NS. Instead of NS, we now use the widely available 1% lidocaine with epinephrine 1:100,000 and dilute the ILTA to 2.5 mg/mL. We postulate that epinephrine 1:100,000 enhances therapeutic efficacy via local vasoconstriction, thus keeping the ILTA in situ longer than NS. This effect allows for a lower concentration of ILTA (2.5 mg/mL) to be effective. Furthermore, epinephrine 1:100,000 may have an independent effect, as suggested in mouse studies.18
Our first case demonstrated the ophiasis subtype of AA (symmetric bandlike hair loss), which has a poorer prognosis and is less responsive to therapy.20 In this patient, prior treatment with topical corticosteroids and ILTA in NS failed to induce a response. After a series of injections with 2.5 mg/mL ILTA in 1% lidocaine and epinephrine 1:100,000, she entered remission. Our second case is one of alopecia subtotalis, which responded quickly, and the patient entered remission after just 3 months of treatment. These 2 cases are illustrative of the results that we regularly get and have come to expect with this treatment.
Conclusion
Our novel modified regimen of 2.5 mg/mL ILTA diluted with 1% lidocaine and epinephrine 1:100,000 has yielded a series of excellent outcomes in many of our most challenging AA cases without any untoward effects. Two cases are presented here. Higher-powered studies are needed to validate this new yet simple approach. A split-scalp or split-lesion study comparing ILTA with and without epinephrine 1:100,000 would be warranted for further investigation.