Key distinguishing features of the most common diagnoses
|HSV||Thrush||Vulval Dysplasia||SCC||Excoriated Scabies|
Possible:Fasting sugar or HbA1c, and (in secondary care) biopsy.
Small Print:Syphilis serology, patch testing.
- Urinalysis: Glycosuria may be present in undiagnosed diabetes presenting with severe or recurrent Candida infection. Fasting sugar or HbA1c to rule out or diagnose undiagnosed diabetes.
- Swab for microscopy and culture: May help in the diagnosis of various infections such as HSV, Candida, chancroid, granuloma inguinale and lymphogranuloma venereum (if STD suspected, then other relevant swabs and blood tests for coexistent infection will be performed at GUM clinic).
- Syphilis serology: If syphilis a possibility (Note: Serology may not become positive for up to 3 months after infection).
- Patch testing: May help in the diagnosis of allergic contact eczema.
- Biopsy (in secondary care): For any persistent ulcer to confirm diagnosis – may reveal carcinoma, vulval dysplasia or underlying skin disorder.
- A diagnosis of HSV can be traumatic for a woman. Spend time discussing the nature of the problem and its recurrent nature, including implications for sexual partners and future pregnancies.
- If the patient suffers recurrent vulval ulceration, offer to see her as an ‘urgent’ during the next attack to visualise the lesions and arrange microbiological testing.
- In obscure cases do not confine the history and examination to the vulva. Lesions elsewhere (e.g. with pemphigus or Behçet’s syndrome) may give the clue needed to make the diagnosis.
- History of travel and sexual contact with travellers is very important as there are a number of ‘tropical’ causes.
- The more straightforward causes (HSV and severe excoriated thrush) usually result in multiple ulcers, with the diagnosis being obvious from the history and examination. Take very seriously any single persistent vulval sore – significant disease is likely.
- If you suspect a sexually transmitted disease, refer urgently to the local GUM clinic for appropriate investigations and contact tracing.
- Remember the possibility of undiagnosed diabetes in severe Candida infection.
- The pregnant woman near term with primary HSV is in danger of transmitting the virus to her newborn – a situation with a significant mortality and morbidity. Contact the obstetrician urgently to arrange probable elective Caesarian section.