Last accessed September 2021.
https://dermnetnz.org/topics/patch‐tests/. Last accessed September 2021.
Prick testing
If a Type 1 allergic reaction is suspected, this is most likely to be due to either semen or latex in the context of vulval symptoms. Prick testing may be required if this type of allergy is suspected, and the patient should be referred to an allergy clinic, where full facilities for resuscitation are available. It detects allergen specific IgE bound to mast cells which degranulate and release histamine, causing a weal at the site of testing. Oral antihistamines should be stopped a few days beforehand.
A small drop of the allergen is placed on the skin, most commonly on the forearm, and then a small prick is made through the liquid with a lancet. A positive control of histamine is used with a negative control of saline. The tests are read after 15–20 minutes, and an urticarial weal of 3 mm or more is regarded as positive.
Patient information about prick testing
https://dermnetnz.org/topics/skin‐prick‐testing/. Last accessed September 2021.
Blood tests
Routine blood tests are of little value in the investigation of vulval disease. They are mainly used in specific situations.
1 Infection Serological tests are useful in some infections but are targeted towards the suspected clinical diagnosis.
2 Immunobullous disease Indirect immunofluorescence is performed on serum and has two stages. First, an unlabelled antibody binds to the target antigen, and in the second stage a fluorescent antibody against the first antibody is used in detection. In immunobullous disease, however, they are generally confirmatory rather than diagnostic. It is used in conjunction with direct immunofluorescent studies.
3 Type 1 allergic reactions A RAST (radioallergosorbent test) is safer than in vivo prick testing if the patient gives a history of anaphylactic reactions. This measures any interaction between the antigen and its specific antibody. The possible allergen needs to be considered and that specific test requested, as it is not a universal test to determine allergy but rather confirms what is suspected.
Imaging
Radiological imaging techniques are rarely needed for the investigation of vulval dermatoses, but are vital in the management of malignant disease and are helpful in other specific situations [13,14]. The main indications for imaging are shown in Table 7.2, and the most appropriate imaging technique should be discussed with a radiologist.
Ultrasound scanning is not widely used in the investigation of vulval lesions as it can be difficult to identify structures. Magnetic resonance imaging scanning (MRI) gives great detail of both the vulva and vagina. The main use of imaging is in the management of malignant disease, where it can be used to delineate the extent of tumours for treatment planning, prognosis, and monitoring for recurrence and response post treatment. Often, a combination of computerised tomography, MRI and positron emission tomography (PET‐CT) is used [15].
Research studies using MRI scanning and Doppler ultrasound had provided a greater understanding of anatomy and function of structures, especially the clitoris [16,17]. Functional MRI of the brain has also been used to study cerebral sexual excitability and its effect on sexual function [18].
Dermoscopy
Dermoscopy is a dermatological technique used mainly in the diagnosis of pigmented lesions. It is not so easy to use on the vulva as special attachments are required in addition to the hand‐held device. This may give additional information when assessing vulval lesions [19], and newer techniques such as reflectance confocal microscopy may be of some use [20].
Table 7.2 Main indications for imaging in vulval disease
| Examples | |
|---|---|
| Congenital abnormalities | Müllerian duct agenesis, Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome Vaginal septa Developmental cysts Cloacal exstrophy |
| Benign lesions | Cysts Fistulae |
| Inflammatory disease | Hidradenitis suppurativa Crohn’s disease |
| Malignant disease | Staging at diagnosis Recurrent disease Monitoring post treatment |
Vulvoscopy
The colposcope, giving a magnification of 8–10 times, is not helpful during examination of the vulva. It provides a very small field of examination and shows up little on keratinised skin. The use of the colposcope for the investigation of cervical and vaginal lesions cannot be extrapolated to the vulva [21]. There is no place for the routine use of toluidine blue and little for acetic acid, as the confusion caused by misplaced emphasis on acetowhite tissue has been considerable, and the light reflection effect produced is non‐specific. It has been shown that 30% of women without any vulval symptoms had acetowhite areas outside the vestibule [22].
Colposcopic examination of the vestibule, vagina, and cervix may, of course, be indicated at some time for certain patients.
References
1 4 Lewis, F.M., Agarwal, A., Neill, S.M. et al. The spectrum of histopathologic patterns secondary to the topical application of EMLA® on vulvar epithelium: clinicopathological correlation in three cases. J Cutan Pathol. 2013; 40(8): 708–713.
2 11 Vieira‐Baptista, P., Grincevičienė, S., Oliveira, C. et al. The International Society for the Study of Vulvovaginal Disease Vaginal Wet Mount Microscopy Guidelines: How to perform, applications, and interpretation. J Lower Gen Tract Dis. 2021; 25: 172–180.
3 12 Klatte, J.L., van der Beek, N. and Kemperman, P.M. 100 years of Wood's lamp revised. J Eur Acad Dermatol Venereol. 2015; 29(5): 842–847.
4 13 Griffin, N., Grant, L.A. and Sala, E. Magnetic resonance imaging of vaginal and vulval pathology. Eur Radiol. 2008 Jun; 18(6): 1269–1280.
5 14 Matos, J., Orazi, C., Sertorio, F. et al. Imaging of diseases of the vagina and external genitalia in children. Pediatr Radiol. 2019 May; 49(6): 827–834.
6 15 Lin, G., Chen, C.Y., Liu, F.Y. et al. Computed tomography, magnetic resonance imaging and FDG positron emission tomography in the management of vulvar malignancies. Eur Radiol. 2015 May; 25(5): 1267–1278.
7 18 Vaccaro, CM. The use of magnetic resonance imaging for studying female sexual function: A review. Clin Anat. 2015 Apr; 28(3): 324–330.
8 21 Micheletti, L., Bogliatto, F. and Lynch, P.J. Vulvoscopy: Review of a diagnostic approach requiring clarification. J Reprod Med. 2008 Mar; 53(3): 179–182.
8 Topical and Non‐Surgical Treatments
Fiona M. Lewis
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