Figure 2 The ulcer on the lower lip disappeared after treatment.
Diagnosis of syphilis remains an intractable problem to clinicians because of its multiple features in morphology. The majority of chancres locate in the genital area. A chancre is a painless, clean, solitary, and indurated erosion in general. Nevertheless, the symptoms and appearances of primary lesions may vary, such as in other sites, with disparate size, amount, depth, shape, or manifest as mucous patches2-3. Besides genitals, the rectum, anus, oral cavity, face, eyes, and fingers are involved4. Extragenital chancres cover about 5%~14% of the cases5. The most common region is oral cavity. One article points out that the tongue is the most affected site with solitary location of oral primary syphilis6. However, it is widely believed that lips are the usual location infected by orogenital, oroanal contact or kissing. No matter in heterosexuals or in MSM, oral sex is prevailing. It is reported that the upper lip is the most common site among men, while the lower lip is among women possibly because of fellatio and cunnilingus7. But our patient was an exception. Whether it associates with his personal habits or not is unknown.
In addition, syphilis is well known as a notorious imitator of various diseases, the characteristics of which are diverse. The chancre of the lips could mimic some infectious diseases, such as herpes simplex, leishmania, tuberculosis, ulcers caused by Epstein Barr virus or cytomegalovirus; and some non-infectious diseases, just like fixed drug eruption, lichen planus, plasma cell cheilitis, squamous cell carcinoma, Behcet disease, and trauma3. When a chancre occurs in the lips or in other regions except genitals, it is difficult to diagnose accurately and without delay.
This case highlights that complete dermatological examination and laboratory inspection are crucial to making an appropriate diagnosis particularly when the initial treatment is ineffective.
REFERENCES
1 Wasserheit J, H Schünemann, Garcia P , et al. WHO Guidelines for the Treatment of Treponema pallidum (Syphilis). WHO. 2016.
2 Rampi A, Danè G, Lissoni A, Vinciguerra A, Indelicato P, Abati S. A case report and a review of the literature of the most common extragenital localization of primary syphilis. B-ENT. 2021; 17(1): 37-41. doi:10.5152/B-ENT.2021.20459
3 Demir FT, Salaeva K, Altunay IK, Yalcin O. An extraordinary case of syphilis presenting with a labial ulcer. Saudi Med J. 2016; 37(11):1261-1264. doi: 10.15537/smj.2016.11.15674
4 Dourmishev LA, Dourmishev AL. Syphilis: uncommon presentations in adults. Clin Dermatol .2005; 23(6): 555-564. doi:10.1016/j.clindermatol.2005.01.015
5 Calvo DF, Cassarino D, Fernandez-Flores A. Syphilitic Chancre of the Lip. Am J Dermatopathol.2020; 42(10): e143-e146. doi: 10.1097/DAD.0000000000001659
6 Zhou X, Wu MZ, Jiang TT, Chen XS. Oral Manifestations of Early Syphilis in Adults: A Systematic Review of Case Reports and Series. Sexually Transmitted Diseases. 2021; 48(12): e209-e214. doi: 10.1097/OLQ.0000000000001538
7 Leão JC, Gueiros LA, Porter SR. Oral manifestations of syphilis. Clinics. 2006; 61(2): 161-166. doi: 10.1590/s1807-59322006000200012
AUTHOR CONTRIBUTIONS
Lingyi Zhao and Yao Ni: Writing-original draft; writing-review & editing.
Jingying Sun: Data collection.
Janzhou Ye: Supervision.
Lingyi Zhao and Yao Ni contributed equally to this work
CONFLICT OF INTEREST STATEMENT
The authors declare no conflict of interest.
DATA AVAILABILITY STATEMENT
Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study. Data sharing does not apply to this article as no new data were created or analyzed in this study.
ETHICS STATEMENT
The patient has consented to publish this information.