Seasonal variation of acute necrotising ulcerative gingivitis in South Africans

OBJECTIVES: To examine seasonal variations in the presentation of acute nec rotising ulcerative gingivitis (ANUG) in a previously unstudied population in Cape Town, South Africa. DESIGN: A descriptive study of all presenting cases of ANUG at a health cen ter over 6 years; patients were examined at one point in time. SETTING: A clinic-based cross-sectional study was carried out among patient s presenting routinely to the oral medicine clinic at the University of the Western Cape, Patients at this clinic were mostly colored and black people , and were of low socioeconomic status. SUBJECTS AND METHODS: All patients presenting to the periodontal clinic wer e examined during the period from 15 March 1992 to 15 March 1998 and interv iews were conducted. A comprehensive clinical intra-oral and peri-oral exam ination was carried out using a dental mirror and blunt probe by three trai ned calibrated dental examiners, The minimum criteria for inclusion as an A NUG patient were painful, bleeding gums with irreversible destruction of th e interdental papillae (cratering) and marginal gingiva, Patients with mult iple small ulcerations not restricted to the gingiva, but including other o ral sites such as the tongue and buccal mucosa were diagnosed as herpetic s tomatitis, Other distinguishing characteristics of ANUG included presence o f a pseudomembrane, odor, a strange taste in the mouth, and hypersalivation , Swabs and biopsies taken to verify the diagnosis when necessary. If there was any doubt as to the diagnosis of the lesion it was not included among the ANUG cases MAIN OUTCOME MEASURE: Presence of ANUG, RESULTS: Among the 19 944 patients presenting for periodontal treatment, 68 4 were found to have ANUG, The ANUG patients consisted of 58% males; 73% of the ANUG patients were between the ages of 5 to 12 years. The majority of ANUG patients presented during the summer (55.4%), 27.7% in autumn and 8.4% during both winter and spring. Significant differences were evident betwee n the numbers seen during the different seasons. CONCLUSIONS: This study de monstrated a significant seasonal variation in the occurence of ANUG in Cap e Town, South Africa.