Case Report
Chikungunya associated vulvitis: case report and literature review

INTRODUCTION

Chikungunya virus is an arbovirus of the Togaviridae family, transmitted by the Aedes Aegypti mosquito¹. The virus was first detected in Tanzania in 1952². However, it has spread to the Americas, Asia, and Europe due to tourism and globalization².

The Chikungunya virus usually manifests itself as a systemic disease. Infected people develop fever, polyarthralgia, myalgia, and maculopapular rash on the skin. Despite mucocutaneous damage, genital lesions are significantly rare (approximately 2.7%)³, mainly described in men. The objective is to describe vulvar lesions related to Chikungunya viral infection.

CASE HISTORY

A 73-year-old white woman attended a vulvar specialty clinic at Hospital Universitário Antonio Pedro, Niterói, Rio de Janeiro, Brazil, (August 3^rd, 2018) complaining about dyspareunia, vulvar burning, and vulvar spotting that had started two weeks before the visit. One month prior to her appointment, she presented a low fever that lasted for one week. After the fever subsided, she developed maculopapular rash with pruritus on her limbs and torso, polyarthralgia, myalgia, asthenia, nausea, and abdominal pain. After one week, nausea and abdominal pain ceased, but the other symptoms persisted and she also presented dyspareunia, vulvar burning, and vulvar spotting (Figure 1).

Figure 1 -

Timeline of the patient’s case.

Due to persistent pain in the vulva, she self-medicated with nimesulide 100 mg every 12 hours for three days and ibuprofen 400 mg once a day for five days with no positive response. She had no other comorbidities, except hypothyroidism (treated with L-thyroxine 50 mcg/d), and had been using hormone replacement therapy (HRT) since the age of 54 (estradiol 1 mg and norethindrone acetate 0.5 mg, continuously).

Vaginal clinical examination revealed good trophism, without petechiae or erosions. The vulva presented hyperemia, edema, and spotting from ulcers in the labia minora and perineum. The size of the ulcers varied from 0.8 cm in diameter, their shape was oval, and there were three of them (Figure 1).

Maculopapular rashes were observed on the neck, torso, and extremities (Figure 1). The culture from vulva and vagina was negative for Candida spp. and group A Streptococcus. The vaginal wet mount smear was normal, revealing Lactobacillus spp. predominance and the absence of leucocytes, Candida spp., and T. vaginalis.

The complete blood count on August 2^nd, 2018, was in the normal range: erythrocytes 4.34x10⁹/L; hemoglobin 133 g/L; hematocrit 39.6%; thrombocytes 247x10¹²/L; leukocytes 5.8x10/L. The creatinine (0.68 mg/dl), alanine transaminase (9 U/L), and aspartate aminotransferase (10 U/L) were also in the normal range.

The patient’s blood test was negative for Herpes simplex 1, 2 (HSV), HIV-1/2, and syphilis. Antibodies tests performed on July 25^th, 2018 were nonreactive for Chikungunya virus IgM and IgG, as well as for Dengue and Zika viruses IgM, with a reactive test result for Dengue and Zika viruses IgG. Antibodies tests against Chikungunya, Dengue, and Zika viruses were repeated on August 23^rd, 2018, rendering a reactive result for Chikungunya virus IgM and IgG, and no change from the prior results against Dengue and Zika viruses. A Chikungunya diagnosis was established by seroconversion in paired specimens (Table 1).

The patient had used non-steroid anti-inflammatory drugs for one month before coming to the clinic, although she had no improvement in the vulvar ulcers and had developed inflammatory arthritis. She was prescribed prednisolone 40 mg once a day for 10 days. When she returned for a control visit two weeks after starting the oral steroid, she had no body rashes or lesions on the genitals (Figure 1), but still maintained arthralgia, myalgia, and asthenia.

DISCUSSION

This work presented a case report regarding genital lesions in a citizen from the city of Rio de Janeiro, Brazil, which is an endemic zone for the Chikungunya virus. This case demonstrates the need for gynecologists to be aware of mosquito-borne viral infections that may cause vulvar symptoms. The differential diagnosis of vulvar ulcers must also include the possibility of Chikungunya, Zika, and Dengue viruses, mainly in regions that are endemic for mosquito-borne viruses¹.

Arthropod-borne viruses are spreading worldwide, which may be due to migration and globalization¹. Chikungunya outbreaks have been recorded in Africa and South America¹. The virus was diagnosed in European countries, as well as in the USA⁴ and Asia⁵. Out of all symptoms observed in Chikungunya infection, polyarthralgia, myalgia, and skin rashes are the most common¹. Unexpected skin damage, such as nasal skin necrosis, have been observed⁶. Multiple aphtha-like ulcers have been described in the scrotal, penal, groin, perianal areas, and in the mouth⁷. However, no reports regarding genital lesions in women were found.

Multinucleated keratinocytes are cytological characteristics observed in herpes simplex, varicella-zoster, and measles infections. However, specific histopathological findings have not been developed for the Chikungunya virus. Riyaz et al. described nonspecific findings such as spongiosis, dermal edema, and perivascular lymphocytic infiltration in Chikungunya cases⁸. As these characteristics cannot be used for the final diagnosis, biopsies of the lesions were not performed on our patient.

The Aedes Aegypti mosquito transmits the virus when feeding on blood⁹. Human dermal fibroblasts, keratinocytes, melanocytes, and macrophages are susceptible to the virus⁵. In the presence of mosquito saliva, IFN-1 gene expression is decreased in fibroblasts⁹. The virus is cytopathic, which results in the apoptotic death of infected cells⁵. This mechanism explains the occurrence of skin ulceration on the external genitals, as well as other symptoms⁵.

It is possible for viral ulcers to heal in two weeks without recurrence¹⁰. Oral prednisolone or topical therapy can be used for symptom relief while anti-viral treatment is unavailable¹⁰.

CONCLUSION

This case serves to alert physicians to consider the possibility of mosquito-borne viruses among other potential causes when seeking a diagnosis for the etiology of vulvar ulcers.