INTRODUCTION

Mpox is a ubiquitous zoonosis transmitted by contact, declared a public health emergency of international concern on August 14, 2024 [1,2]. Central Africa is the most affected region [2]. During the disease, the symptomatology is dominated by cutaneous involvement. This localization helps guide the diagnosis [1]. In 2023, cases of sexual contamination of mpox were reported in West Africa [3,4] without specifying the mechanism. Herein, we report two transmissions of mpox with inoculation chancres.

Case 1

A twenty-year-old adolescent boy presented with a pubic chancre two days after sexual contact (Fig. 1). A disseminated papular rash with progressive onset appeared one week after the chancre. The papules were umbilicated and non-pruritic. The patient had a fever of 38°C, without chills. He had inflammatory inguinal lymphadenopathy. Serological tests for syphilis, HIV, and chlamydia were negative. A sample of serum from the chancre revealed no bacteria. PCR performed on a papule was positive for mpox.

Figure 1: Penile chancre and ambilicated pubic papules.

Case 2

This case involved a 22-year-old man who presented to the emergency department with disseminated papular lesions predominantly affecting the pelvic limbs and abdomen. These lesions had been progressing for one week. Clinical examination revealed a linear, oozing ulcerated lesion in the balano-preputial sulcus (Fig. 2). This painless chancre preceded the eruption by five days, and bilateral, tender, and firm lymphadenopathy was noted. Syphilis serology was negative. There were no treponemes or Donovan bodies on direct examination of the chancre. PCR of one papule was positive for mpox.

Figure 2: Chancre of the balano-preputial groove and ambilicate papules on the thighs.

DISCUSSION

These were both patients with mpox with typical skin lesions preceded by chancres in the genital area several days after sexual contact. The notion of a sexually transmitted infection has been raised for mpox [4,5]. Mpox typically presents with an incubation period of twelve days on average, followed by an infectious syndrome and a maculopapular eruptive phase of fisiculopustules and diffuse crusts, followed by polyadenopathy [1]. The rash appears to predominate in the anogenital regions. Inoculation chancre is not classic [6]; its presence could mislead the diagnosis and suggest pathologies such as herpes, chancroid, or primary syphilis. The chancre in MPOX does not appear to have a typical characteristic. In both of our cases, it has irregular shapes, detached edges, and an oozing base. Harnessed lymphadenopathy is present in both cases. These bilateral, inflammatory inguinal lymphadenopathies are firm and of variable size. Chancres should be systematically sought in other mucous membranes. It would be wise to routinely perform PCR for mpox on a chancre in endemic areas.

There is, therefore, a variability of clinical forms, ranging from simple forms to severe forms [7]. Diffuse skin forms are the most described [8], but mucosal locations, especially genital ones, represent a particular epidemiological and diagnostic interest [9,10].

CONCLUSION

The etiopathogenesis of mpox infection still raises questions. This pathology may be considered an STI for which an inoculation chancre should be systematically sought.

REFERENCES

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