A 34-year-old man was referred to the Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand from the Department of Medicine, King Chulalongkorn Memorial Hospital with a chief complaint of a painful and burning sensation of lip and oral mucosa when consuming food. The patient was an ex-intravenous drug user who had acquired HIV and hepatitis C (HCV) genotype 1 infections for 12 years possibly from multiple heterosexual partners or intravenous drug use. He had tuberculosis (TB) of lymph gland and had been treated with anti-TB drugs for one year. Six months after the TB treatment, HAART was started with daily doses of 600 mg AZT, 300 mg 3TC, and 800 mg of EFV. Monitoring of drug efficacy was assessed periodically. Baseline plasma HIV-1 RNA viral load (VL) was 97,500 copies per mL (4.99 log) before commencing HAART. He responded quite well to the treatment and the HIV-VL fell below the limit of detection of less than 50 copies per mL after 6 months of treatment. The patient's immune status was improved with the absolute CD4+ T cell count at baseline, 6 months, and 30 months as 31, 168, and 287 cells per muL, respectively. 
The patient denied drug hypersensitivity, smoking, and alcohol consuming habits. The oral lesions developed two and a half years after beginning HAART. Oral examination revealed erosive lesions of the lip and right and left sides of buccal mucosa. The lesions had slightly raised keratotic white reticular striae and white papules on an extensive background of erythematous mucosa with deep ulcerations (Figures 2(a), 2(b), and 2(c)). Clinical scores of the right and left buccal mucosa as well as the lip lesions were 5, 5, and 4, respectively. Both lateral sides of the tongue displayed nonpainful and very mild white plaques. Areas of redness corresponding to the sharp edges of the adjacent teeth were also observed. The OLDR diagnosis of lesions at the lip and buccal mucosa was based on the history of medications and the incidence of initial eruptions of the lesions as shown in Figure 1. Management in this patient was focused on relieving the symptoms. Topical fluocinolone acetonide 0.1% orabase, solution, and sodium bicarbonate mouthwash were prescribed. Smoothing of sharp edges area of teeth resolved in healing of the red area at lateral sides of the tongue, and long-term follow-up was planned. While the use of topical steroid relieved the patient of oral pain, the lesions themselves did not resolve. After treating the oral lesions for 19 months, a liver biopsy was performed and showed fibrosis stage 3 from chronic HCV type 1 hepatitis. Pegylated interferon and ribavirin were planned to be prescribed to the patient in management of the HCV infection. Due to the myelosuppressive effect of AZT, it was decided to withdraw the patient from AZT prior to interferon administration. AZT was switched to tenofovir (TDF) 300 mg, but EFV and 3TC were continued. Two months after the withdrawal of AZT and with the local topical steroid treatment, only very mild white papules at right buccal mucosa remained, and the clinical pain score at this site was 1, while other sites were in complete remission (Figure 3). Pegylated interferon and ribavirin therapy began 1 year after the cessation of AZT.