A 29-year-old man was transferred to the Department of Odontology by his general practitioner for an acute outbreak on his oral mucosa which prevented him from eating. The lesions had appeared 8 days earlier, and before that, the patient had suffered from a slight temperature, headaches and a sore throat. NSAIDs and cetylpyridinium lysozyme had been prescribed as a treatment. The patient also reported having suffered from successive episodes of labial herpes before the outbreak of symptoms.
General symptoms, such as asthenia and a fever, were observed. The initial cardiopulmonary examination was normal. There was no swelling of the lymph nodes, liver or spleen. During the oral examination, multiple but irregular oval-shaped erosions on an erythematous surface were noted on the palate (Fig. 1), the inside of the cheeks (Fig. 2) and the palatoglossal arches. His tongue was swollen, and an impression of his teeth around the edge could be observed (Fig. 3). A fibrous coating covered the mucosa on both sides of the tongue and across the floor of his mouth (Fig. 4). We also noted an ulceration of the urethral meatus and a bilateral conjunctivitis with no obstruction to his vision (Fig. 5). The rest of the tissue was normal. Serology for M. pneumoniae proved positive. However, herpes simplex virus by polymerase chain reaction was negative. C-reactive protein reached 54 mg/L.
A 7-day treatment regime was initiated made up of orodispersible prednisolone 30 mg/day and valaciclovir 500 mg morning and night. To facilitate eating and to relieve the patient from pain, lidocaine gel and tramadol were also prescribed.
On the 7-day check-up, the urethral and eye lesions had completely healed up. However, some oral erosions persisted. The decision was made to continue the prednisolone 30 mg/day for 7 days, with a recommendation to continue with the lidocaine gel and paracetamol.
A new blood test for M. pneumoniae was carried out after 15 days to eliminate a potential false positive in the absence of associated pulmonary symptoms. The IgG and IgM anti-M. pneumoniae levels corresponded to those of an acute infection.
Seven months later, the patient came back for another consultation for a similar outbreak: first, there were oral lesions, followed by conjunctivitis and fever, but this time there were no genital related symptoms. The patient was once again treated with prednisolone and valaciclovir. We noted an improvement within a few days. The prednisolone was stopped, and the valaciclovir was reduced to 500 mg/day. One week later, there was a new outbreak of EM. The valaciclovir was stopped and replaced by 1 mg/day of colchicine for 3 months. The patient has not suffered from any other outbreaks since the start of the treatment after a 7-month observation period.