18Vulval Infection – Nonsexually Transmitted
The two most common vulval infections not transmitted via a sexual route are candidiasis and bacterial vaginosis. In both cases, the normal balance of the flora of the vulva and vagina is upset, causing overgrowth of organisms leading to symptoms.
However, there are several less common infections that occur on the vulva that are not transmitted via sexual contact. Many of these are rare in the developed world but are listed in Table 18.1. Advice should be sought from experts in tropical medicine regarding diagnosis and management where relevant.
Table 18.1 Nonsexually transmitted vulval infections.
| Clinical features | Diagnosis | Treatment | ||
| Nematode infection | Threadworm infection(Enterobius vermicularis) | Common infection in children; anal and vulval pruritus | Identification of the threadworms or eggs on perianal skin – can be seen by applying adhesive tape to the skin and examining microscopically | Piperazine or mebendazole |
| Filariasisa | Lymphoedema and elephantiasis | Histology | Diethylcarbazine in increasing doses. Surgery may be required | |
| Trematode (fluke) infection | Schistosomiasisa | Usually occurs before puberty with granulomatous nodules; swelling and scarring can occur | Ova are seen in the urine. ELISA tests available | Praziquantel |
| Protozoa | Leishmaniasisa | Large ulcers that can be similar to those seen in syphilis or donovanosis | Histology or specialized culture | Sodium stilbogluconate or antimony preparations |
| Amoebiasisa caused by Entamoeba histolytica | Abscesses on vulva, perineum or cervix with lymphadenopathy | Amoebae may be seen in the ulcers or on scrapings from cervix | Metronidazole | |
| Mycobacterial infection | Tuberculosisa | Vulval involvement less common than upper genital tract; nodules, ulcers and scars occur; more common in immunosuppressed patients | Histology | Antituberculous treatment |
| Leprosya | Can be direct inoculation of the vulva or involvement by haematogenous spread | Expert advice | ||
| Other bacterial infections | Actinomycosis | Actinomycosis species can infect intrauterine devices | Culture and histology | Penicillin is first line, but Tetracyclines, clindamycin and erythromycin are alternative treatments. |
| Mycoplasma | Ureaplasma and mycoplasma species may be found in the vagina in asymptomatic patients; Bartholin’s abscesses may occur | Culture and histology | As for actinomycosis |
Note:
aAsk for expert advice on investigation and management.
Bacterial Infections
- Bacterial vaginosis.
- Erythrasma.
- Staphylococcal and streptococcal infection.
Bacterial Vaginosis
Bacterial vaginosis (BV) is the commonest cause of a vaginal discharge in women during the reproductive years and is due to an imbalance in the normal flora causing overgrowth of Gardnerella vaginalis. It has been associated with pre‐term birth and endometritis.
Clinical features
The classic feature is of an offensive profuse vaginal discharge. Inflammation is not generally associated, but the discharge can cause an irritant vulval dermatitis in some women.
Diagnosis
The Amsel diagnostic criteria include a white discharge, vaginal pH .4.5, clue cells on direct microscopy and a fishy odour with the addition of 10% potassium hydroxide.
Treatment
Metronidazole or clindamycin are recommended.
Further reading
- Donders, G., Zodzika, J. and Rezeberga, D. (2014) Treatment of bacterial vaginosis: what we have and what we miss. Expert Opinion on Pharmacotherapy 15, 645–657.
Useful Web Sites for Patient Information
BASHH patient information:
- http://www.bashh.org/documents/BV%20PIL%20Screen%20‐%20Edit.pdf (accessed 14 September 2016)
CDC guidance:
- http://www.cdc.gov/std/tg2015/bv.htm (accessed 14 September 2016)
UK National Guideline for the Management of Bacterial Vaginosis 2012:
- http://www.bashh.org/documents/4413.pdf (accessed 14 September 2016)
Erythrasma
Erythrasma is an infection caused by Corynebacterium minutissimum, a Gram‐positive aerobic bacterium It is found on normal skin but particularly favours moist environments, therefore vulval involvement is common. Predisposing factors include immunosuppression, diabetes and obesity.
Clinical features
The areas are well demarcated (Figure 18.1) with superficial scaling at the edge (Figure 18.2). There may be a red / brown discoloration to the plaques with lesions at other sites, including the axillae and under the breasts.
Figure 18.1 Erythrasma.
Figure 18.2 Scaly edge to the plaques.
Differential diagnosis
Tinea cruris is the major differential diagnosis and the two infections can sometimes occur together.
Diagnosis
Microscopy of skin scrapings (see Chapter 5) can identify the organism. The diagnosis can also be made by using a Wood’s lamp as affected areas will show a coral‐pink fluorescence due to the presence of a porphyrin.
Basic Management
Topical treatment with fusidic acid cream or topical erythromycin may be effective. Oral erythromycin 250 mg four times a day for 2 weeks is used in more severe infections.
Useful Web Site for Patient Information
DermNet:
- http://www.dermnetnz.org/bacterial/erythrasma.html (accessed 14 September 2016)
Staphylococcal and Streptococcal Infections
These two common pathogenic bacteria cause a range of clinical patterns of infection (see Table 18.2).
Table 18.2 Staphylococcal and streptococcal infections.
| Staphylococcus | Streptococcus | Either |
| Folliculitis | Streptococcal perianal dermatitis | Cellulitis |
| Bartholin’s gland abscess | Necrotizing fasciitis | |
| Toxic shock syndrome | ||
| Staphylococcal scalded skin syndrome |
Folliculitis
Staphyloccous aureus is the usual agent responsible for folliculitis, a pustular infection around hair follicles, boils and abscesses. The increasingly recognized variant of S. aureus, PVL (Panton Leucocidin Valentine) can cause infection in the vulval area.
Pathophysiology
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