Oral thrush is an overgrowth of Candida albicans, a normal organism in the gastrointestinal tract and mouth. It commonly occurs in people who are immunosuppressed, especially those with HIV/AIDS. In severe cases of oral thrush, the person has difficulty swallowing, which limits the ability to consume nutritious meals and take oral medicines.

Sub-Saharan Africa has the highest number of people living with AIDS. First-line primary care treatment for oral thrush in such patients is gentian violet 0.5% solution, which is applied to the inside of the mouth 3 times a day. The problem with this treatment is that it must be applied at a clinic, which requires that the person be healthy enough for travel and that funds are available for transportation. Plus, gentian stains the mouth purple, which causes the person to be stigmatized as having HIV/AIDS. Due to financial constraints, the Moretele Hospice in South Africa routinely treats oral thrush with lemon (Citrus x limon, Rutaceae) juice applied directly to the mouth or a lemongrass (Cymbopogon citratus, Poaceae) infusion that is made from lemongrass plants grown and dried at the hospice. According to the authors, the 2 remedies are reported to be highly efficacious and have been used at the hospice since it opened in 1997. A randomized controlled study was conducted to compare the efficacy of these natural products to standard first-line treatment (gentian).

Ninety patients with oral thrush were recruited from the HIV/ AIDS support group at the Moretele Hospice to participate in this randomized, controlled, open-label comparative study. The patients were randomly assigned to receive 1 of 3 treatment schedules: (1) Control treatment of gentian violet aqueous solution 0.5% (brand not identified) applied topically 3 times/day and continued for 2 days after clinical cure; (2) Lemon juice was squeezed from a fresh lemon and 20 mL of juice was mixed with 10 mL water. Half of the mix was swished in the mouth and spit out; the remaining mix was kept in the mouth in the affected area for as long as possible and then swallowed. Two to 3 drops of pure lemon juice 3 times/ day were then used for the next 10 days or until clinical cure; (3)

12.5 mL dried lemongrass was infused in 500 mL boiling water for 10 minutes and then cooled. On day 1, 125 mL of infusion was consumed, then at least 250 mL was consumed 2 times/day for 10 days. A fresh infusion was made every 24 hours.

The maximum treatment period was 10 days. Patients could withdraw from the study if there was no improvement after 2 consecutive days of treatment, if pain or difficulty swallowing increased compared to day 1, or if the patient found any adverse effects unacceptable. Adverse events (AEs) were recorded if patients spontaneously reported them.

The 3 groups were similar at baseline, based on age, gender, body mass index distribution, days with symptoms, and thrush scale of severity. The AEs for the gentian violet group were purple discoloration (a predictable effect), cracked lips, and dry mouth. Many of the 12 patients in the gentian violet group who withdrew did not want to continue treatment because they were embarrassed about the color of their mouths. The lemon juice group reported a changed taste in mouth and abdominal cramps, and 12 withdrew. One patient in the lemongrass group had an increased appetite, but 6 withdrew. One patient in the gentian violet group and 7 in the lemongrass group were lost to the study due to incomplete documentation. In the intent-to-treat population, there was no significant difference in the proportion of patients treated successfully with gentian violet (n = 30) vs lemon juice (n = 30) or gentian violet vs lemongrass (n = 30). In the participants who completed the trial, those who were clinically cured included 16 using lemon juice (n = 18) and 15 using lemongrass (n = 17), which is significantly more (P = 0.02 and P < 0.05, respectively) than the 9 who used gentian violet (n = 17).

The authors conclude that both lemon juice and lemongrass are better than gentian violet at treating oral thrush in HIV/AIDS patients. Lemon juice stings but cures within a couple of days, and gentian violet had poor compliance due to the discoloration. The lemongrass infusion had the lowest number of AEs, and compliance was good.

In South Africa, inadequate finances limit the use of effective therapies, so finding a cost-effective alternative is paramount. According to the authors, lemon trees and lemongrass can be grown in any garden in South Africa, so the results of this study may help these treatments become more widespread. A limitation of this study was that it had a small number of participants, and a large-scale study should be conducted. Also, the study should include multicenters, rather than just one.

—Heather S. Oliff, PhD