A 29-year-old man was referred by the Department of Internal Medicine regarding lesions in his oral cavity. He complained about pain in the lower anterior jaw gum and lower lip for a week and had a fever history in the last 2 weeks. He was diagnosed by the Internist with HIV stage IV with wasting syndrome, hypothyroidism, latent syphilis, chronic hepatitis B, moderate dehydration et causa inadequate intake, stage 1 acute kidney injury (AKI), inflammatory anemia, and malnutrition. On extra oral examination, we found exfoliative lips, and the lips looked pale. From the intra-oral examination, we found multiple irregular painful erosion on the lower labial mucosa. The anterior mandibular gingiva was edematous and tended to bleed and there was an excruciating grayish-white plaque in the region of teeth 33 to 43 (Figure 3). On the upper anterior gingiva, reddish bands appeared on the attached gingiva of teeth 11 and 21 (Figure 3). Laboratory examinations showed reactive TPHA with titer 1:5120 and reactive VDRL with titer 1:64, reactive hepatitis B e antigen (HBeAg), reactive HBsAg, non-reactive anti-hepatitis c virus (HCV). Examination of Mycobacterium tuberculosis using the Assay method did not find Mycobacterium tuberculosis bacteria. The lesions on the gingiva were diagnosed with necrotizing ulcerative gingivitis (NUG). The lesion on the maxillary anterior gingiva was diagnosed as linear gingival erythema. 
Necrotizing ulcerative gingivitis in this patient was treated with 1.5% hydrogen peroxide irrigation and rinsed with saline solution. Patients were also asked to rinse their mouth with 0.2% chlorhexidine gluconate 3 times a day and regularly clean their teeth and tongue at least 2 times a day. We did not prescribe any antibiotic because Internal Medicine had given azithromycin for systemic infection. After 7 days of therapy, the lesions improved (Figure 3).