Diagnostic and Therapeutic Procedures

Diagnostic and Therapeutic Procedures

Libby Edwards

Unlike many specialties, diagnostic and therapeutic procedures for outpatient anogenital diseases generally are limited. For skin disease, the area of abnormality is visible, so that the evaluation and management of this area rarely require expensive imaging or depend upon sophisticated equipment or the assistance of multiple specialties. However, complex urologic and gynecologic surgical procedures to correct structural abnormalities are beyond the scope of this book.

For the majority of patients, the relevant aspects of evaluation are a brief and directed history, careful visual examination, microscopy of vaginal fluid or the scale of some skin conditions, and, at times, a fungal culture or a skin biopsy. The careful inspection of the skin requires only a good light, stirrups for women, and, often, simple magnification of a headband magnifier that can be ordered online for under $30 (Fig. 4-1). Examination with a colposcope and use of acetic acid or toluene blue are not needed.1 In fact, a recent study of 400 women showed an overall concordance rate of only 53.9% of the vulvoscopic appearance of HSIL (high-grade squamous intraepithelial lesion), LSIL (low-grade squamous intraepithelial lesion), and carcinoma compared to the biopsy findings. 2 However, familiarity with normal structures and variants of anogenital skin is important (see Chapter 1), as is an understanding of variable presentations of classic skin diseases in damp, thin skin folds. Often, the diagnosis of skin disease on the genitalia is obvious, with classic signs such as the crinkling white skin of lichen sclerosus and further evaluation for the primary abnormality is unnecessary.

However, the typical morphology of skin disease on dry, keratinized skin often is modified in the folds of genital skin. Intertriginous areas often are somewhat pink normally, and moisture, heat, and friction obscure scale and change the appearance of dermatoses (Fig. 4-2). When the morphology of skin diseases is atypical or nonspecific, there are methods for narrowing down possibilities when a firm diagnosis cannot be made and for formulating empiric therapy.

For those diseases that display objective abnormalities, the cause is nearly always infection, tumor, or noninfectious inflammation that is often immune mediated. Even when the exact diagnosis cannot be ascertained by examination or biopsy, infection and tumor can be ruled out by cultures and biopsies. Most visible skin disease that is not tumor or infection is corticosteroid responsive. Sometimes a definitive diagnosis cannot be made, and when easily diagnosed and dangerous conditions have ruled out, a trial of presumptive therapy is reasonable and often beneficial.

The management of genital skin diseases is usually inexpensive, but often time-consuming, because careful and sensitive patient education generally is required, and attention to multifactorial processes such as secondary infection, estrogen deficiency, and irritant contact dermatitis is important. Except for radiation therapy and the surgical removal of growths, the therapy of most genital disorders is medical, consisting of self-administered oral and topical medications. There are several office procedures, however, including intralesional therapy, cryotherapy, unroofing procedures for cysts and sinus tracts of hidradenitis suppurativa, and lysis of adhesions of scarring dermatoses that are simple and enhance the patients’ quality of life.

Diagnostic Procedures

The diagnostic procedures for genital skin diseases are performed in the office or at the bedside. Only careful eyes, a microscope, glass slides and cover-slips, 10%-20% potassium hydroxide (KOH), and normal saline are required for the majority of patients. Although these procedures are easy and quick to perform, the interpretation of the microscopic findings requires experience. Therefore, unexpected results or a poor response to therapy should be further evaluated by appropriate cultures, molecular studies, or biopsies to corroborate the microscopic findings.

The use of a speculum allows for visualization of the vaginal walls and sampling of vaginal fluid for microscopic examination and culture. Clinicians who care for women with vulvar dermatoses or vulvar pain should invest in a small narrow, straight Pederson speculum, which produces far less distention of the introitus and less pain on insertion than does the standard Graves speculum with its bulbous tip (Fig. 4-3). Although the visualization of the cervix is more difficult with the Pederson speculum, the cervix is generally not crucial to the diagnosis
and management of vulvovaginal skin diseases. A pediatric speculum is occasionally useful for those patients with severe pain with insertion of a speculum.

Clinical Examination (See Also Chapter 3)

By far the most important diagnostic “procedure” is a careful examination of the skin. History is relatively unimportant, since this area is visible. For older providers, inexpensive magnification is important, and for all examiners, proper exposure of the area and a good light are necessary.

Dermatologists are familiar with the diagnosis of skin disease by morphologic appearance. However, skin disease in the genital area is modified by the location that exhibits less scale, less well-demarcated plaques, and frequent erosions rather than intact blisters. Formulation of a diagnosis is challenging at times, but an organized approach can be extremely useful (Table 4-1).

To help deal with this difficulty, the International Society for the Study of Vulvovaginal Disease (ISSVD) has developed a clinical diagnostic classification based on the appearance of the skin for vulvovaginal skin disease, which is also useful for male genital disease (Table 4-2). This classification forms the basic outline for this book. When the diagnosis is not obvious from the appearance of the skin alone, a biopsy is generally performed. Unfortunately, when the presentation of the skin disease clinically is nonspecific, the biopsies are often nonspecific as well. However, even when a biopsy is not diagnostic, the biopsy adds information. A second ISSVD classification,
that of the appearance on biopsy, can be used (Table 4-3). Cross-referencing the clinical diagnostic classification with the histologic classification narrows the differential diagnosis. The best dermatopathologists, when the diagnosis is not obvious, give not only a microscopic description with pertinent negatives but also suggest possible clinical diagnoses that would be consistent with the histology. For other clinicians without this benefit, the histologic classification can be used to glean this information.

For example, the differential diagnosis of a red patch can be gleaned from Table 4-2; item 2 is red patches and plaques, sending the clinician to Chapter 5. This chapter contains diseases in the differential diagnosis of red patches and plaques, including; allergic or irritant contact dermatitis, atopic dermatitis (eczema), lichen simplex chronicus, Candida, lichen planus, Zoon vulvitis/balanitis, Hailey-Hailey disease, extramammary Paget disease, differentiated vulvar intraepithelial neoplasia, penile intraepithelial neoplasia, high-grade squamous intraepithelial neoplasia, and eczema from rubbing and scratching superimposed on dermatitis; the differential diagnosis can be narrowed to eczema (atopic dermatitis) and contact dermatitis.

Cytologic Smears

The microscopic evaluation of scale and vaginal fluid is crucial to the diagnosis of some types of vaginitis and for the diagnosis of tinea in a setting that could alternatively represent psoriasis, contact dermatitis, lichen simplex chronicus, erythrasma, etc. In the case of the evaluation of vaginal infections, even a self-collected swab can be far, far more useful than a telephone diagnosis on the basis
of symptoms.3 We have found that women can be given a culturette tube to capture vaginal fluid and mail to the office with excellent concordance to testing in the office for candidiasis, bacterial vaginosis, and estrogen maturation index. Most culturette brands yield obvious sheets of buds after 48 hours, but some can take as long as a week to become positive (Fig. 4-4).

Sadly, more and more gynecology offices have no microscope, severely limiting the evaluation of vaginitis.

Fungal Preparations

Fungal preparations are essential to the diagnosis of some anogenital diseases. Men generally interpret all anogenital itching as produced by “jock itch” or tinea infection, whereas women assume that all vulvovaginal itching represents a yeast infection. The confirmation or elimination of these conditions is vital.

KOH 10%-20% solution is a basic agent that dissolves the keratin of epithelial (squamous) cells, allowing spores as well as fungal hyphae and pseudohyphae to be seen more clearly. The reliability of this test depends on the choice of the lesion to be sampled, adequate dissolution of cells so fungal elements are best visualized, and the experience of the examiner in distinguishing fungal elements from artifacts such as hair, fabric fibers, cell membranes, and fractures in crusts.

A fungal preparation of vaginal fluid is much easier than that of scale from skin, because there are fewer artifacts, and the fragile mucosal squamous epithelial cells dissolve quickly. However, some infections may produce a small number of organisms that are missed on microscopic examination. Vaginal secretions are collected with a cotton-tipped applicator from secretions remaining on the blade of the withdrawn speculum, from a pool of secretions within the vagina (avoiding the cervical os) or by gently rolling the cotton tip along the vaginal walls when there is no pool of vaginal secretions. Then, a dot of vaginal fluid is touched to the slide, rather than smeared on, which can distort the preparation. Care should be taken to avoid a too-thick preparation that prevents a careful examination. If the vagina is dry and there are no obvious secretions, then the cotton tip should be rolled onto the slide.

The best areas of skin to sample for tinea cruris (dermatophytosis) or cutaneous candidiasis include the peripheral scale from plaques of tinea, and pustule roofs, or white, cheesy material produced by suspected yeast. These elements are removed by gently scraping with the rounded surface of a number 15 scalpel blade. In the damp areas of the genitalia, the sample usually adheres to the scalpel blade and can be wiped onto the glass slide. Dry, hairbearing skin should be moistened with water so that the scale sticks to the blade until it is smeared onto the slide.

Once the vaginal secretions or scale is applied to the glass slide, a drop of KOH is placed on the material to dissolve the keratin from cells and to enhance the visibility of fungal elements. A coverslip is applied, and firm pressure with slight agitation of the coverslip with the back of a fingernail or a pencil eraser (to avoid distracting fingerprints on the coverslip) flattens and augments the dissolution of keratin. Although the nonkeratinized epithelial (squamous) cells in vaginal smears deteriorate quickly after exposure to KOH, the scale of keratinized skin requires further attention to dissolve so that fungi and yeasts can be easily detected. The examiner can use KOH mixed with dimethyl sulfoxide or DMSO (available at medical supply facilities) to enhance dissolution. Or the examiner can simply allow 10-15 minutes for the KOH to disintegrate the cells. In addition, scale dissolves more quickly after addition of KOH if the slide is gently warmed over an alcohol flame.

Fungal elements are best visualized by lowering the condenser to increase the contrast between fungi elements and epithelial cells. Spores, buds, and hyphal elements appear refractile and sometimes very slightly green, and these are much smaller than common artifacts, such as hair and fibers. Dermatophytes appear as branching, septate hyphae that cross over cell membranes (Fig. 4-5). Candida albicans and Candida tropicalis appear as budding yeasts with hyphae or nonseptate, branching pseudohyphae (Fig. 4-6). At times, cell membranes in the process of dissolving resemble hyphae or pseudohyphae (Fig. 4-7). When this is suspected, pressure and slight agitation of the coverslip disrupts the cell membranes more efficiently and differentiates between true hyphae/pseudohyphae and this artifact. Non-albicans/tropicalis species of yeast are characterized by buds without mycelia (Fig. 4-8). The specific dermatophyte species of tinea cruris cannot be recognized from the smear. A culture is required to speciate a dermatophyte on the rare occasion that this is desired. Oil droplets and air bubbles can be
confused with yeast buds at times, but the variability in size and very round shape distinguish these from yeast buds (Fig. 4-9). “Tinea” versicolor (which occurs uncommonly in the genital area) is a misnomer because it is a yeast rather than a dermatophyte or true “tinea” infection. It exhibits short, curved hyphae and spores/buds microscopically (Fig. 4-10).

Saline “Wet Mount” Preparation (See Also Chapter 14)

Information from an examination of vaginal secretions is sometimes extremely important in the evaluation of the vulva since irritating or infected vaginal secretions touch the vulva. A microscopic evaluation of vaginal secretions using normal saline under a coverslip permits an evaluation of the morphology of cells, a screen for inflammation and estrogen effect, and a crude survey of colonizing and infecting organisms. The diagnosis of bacterial vaginosis can be made only with a wet mount that shows clue cells and the absence of lactobacilli in conjunction with a positive whiff test and a pH >4.5.

A common mistake in the interpretation of a wet mount is a quick directed scan for yeast and clue cells, although even more common is submission of secretions for expensive molecular testing for infection with the incorrect assumption that this covers all causes of vaginitis. Secretions are collected as described above for evaluation for Candida spp. However, the secretions are transferred from the cotton-tipped applicator by touching (if abundant) or gently rolling (if scant) onto the glass slide. Care should be taken to avoid the thick application of secretions, which interferes with visualization.
Some clinicians prefer inserting the cotton-tipped applicator into a test tube and adding a few drops of saline to dilute the secretions and separate the cells to better evaluate the morphology. This author has tried both methods but has found that the evaluation of white blood cells is problematic when the vaginal secretions are first diluted. First, inflammatory cells stick to the sides of a test tube (and the sides of a culturette tube if secretions on the cotton-tipped applicator are inserted into a culturette tube for later evaluation). Second, the sample is diluted so that detection of lactobacilli can be difficult.

A knowledge of the normal components of vaginal secretions and common artefacts is needed to evaluate vaginal secretions beyond the absence of yeast, clue cells, and trichomonads (Fig. 4-11). Mature epithelial cells shed from a well-estrogenized vaginal epithelium appear as large, often folded, polygonal cells with abundant cytoplasm and a small, condensed nucleus. A crude maturation index can be performed, in which the degree of maturation of epithelial cells is estimated (and this is all that is needed for the evaluation of vulvar discomfort). Immature epithelial cells, or parabasal cells, are much smaller and rounder than mature cells, with proportionately larger nuclei (Fig. 4-12). These less mature cells are seen in several settings and serve as a marker for atrophic, estrogen-deficient vaginal epithelium, erosions of the epithelium, and rapidly proliferative inflamed vaginal mucosa. Clue cells are a distinct abnormality of epithelial cells that are pathognomonic for bacterial vaginosis. These clue cells occur when bacteria adhere to epithelial cells and obscure the sharp borders of the cells so that the
edge appears ragged and the cytoplasm appears granular (Fig. 4-13).

Although many different organisms are normal vaginal inhabitants, lactobacilli are the most common bacteria seen on a saline preparation of normal vaginal secretions of a well-estrogenized woman. These appear as rods of variable lengths. Occasionally, lactobacilli attach to each other from end to end, to form very long filaments, formerly believed to represent Leptothrix (Fig. 4-14). These strands are sometimes confused with the hyphae of C albicans or C tropicalis. However, the filaments of lactobacilli are smaller in caliber than yeast, and these are nonbranching, when compared to the hyphae and pseudohyphae of C albicans.

Other parameters evaluable from a saline preparation are the numbers and types of white blood cells. Leukocytes are regularly present, normally at a ratio of 1:1 or less with epithelial cells. Inflammation, which can be produced by Trichomonas infection, an irritated or superinfected atrophic vagina, erosive vaginal dermatoses, or desquamative inflammatory vaginitis, is characterized by an increase in white blood cells (Fig. 4-15). The inflammatory cells can be either lymphocytes or neutrophils, but there is no published information on the implications of this difference. Some clinicians believe that bacterial infections (excluding bacterial vaginosis) are more likely to be characterized by neutrophilic inflammation, whereas noninfectious inflamed dermatoses, such as lichen planus, are more likely to result in an influx of lymphocytes. This author has found this distinction to be unreliable.

Microscopic Examination for Infestations

The three infestations that produce marked anogenital symptoms are scabies, pinworms, and pubic lice. Lice and their nits can be seen by the very careful naked eye or the simple magnifiers mentioned earlier, although a lowpower microscopic examination of a hair with a nit is more conclusive.

The most important aspects of an evaluable scabies preparation are the correction selection of a burrow and the aggressive rather than gentle removal of the affected epidermis. The microscopic confirmation of scabies is often difficult and requires practice. The average patient with scabies has few mites despite widespread rash, most of which results from the immunologic response to the mite and the secondary eczema produced by itching and rubbing. Although one would expect a burrow to present as a linear papule, the burrow of these microscopic parasites actually appear as burrow an edematous, oval papule, with the best burrows for sampling being unscratched. Usually, even those patients with genital
scabies have more accessible and appropriate burrows between fingers or on the ventral wrists. The classic nodules of scabies most common on the penis and scrotum are not appropriate for scraping, as the mite is usually deeper in the skin. A thin layer of epidermis is shaved with a number 15 scalpel blade, and the skin specimen is laid flat on a glass slide. A drop of normal saline or immersion oil is applied to the material, and a coverslip is affixed. The presence of ova, feces (scybala), or the mite itself is definitive evidence of infestation (Fig. 4-16). The mite, if present, is not subtle and is rarely missed. Eggs are regular, smooth, and fairly large, so they also are usually identified without difficulty. Scybala, however, are regular, clustered, small, golden brown globules that require some experience to identify with confidence. A negative scraping does not eliminate scabies as a diagnosis. A biopsy adds information in the absence of a positive scraping, by either identification of the mite or by the presence of eosinophils, suggests a parasite of some type. A biopsy can also be useful in the patient with genital scabietic nodules but no burrows since that biopsy specimen will be interpreted as an arthropod bite consistent with but not diagnostic of scabies, although the mite usually is not identified.

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Jan 8, 2023 | Posted by in GENERAL | Comments Off on Diagnostic and Therapeutic Procedures
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