Possibly because of embarrassment, patients with genital LSC rarely seek medical attention until the problem has been present for weeks or months. Often, the itching arises subtly, but in women, a specific event, most often vaginal discharge (perceived to be a yeast infection), will be identified by the patient as the initial trigger. In either setting, once itching has occurred, scratching almost inevitably follows. Most patients describe the itching as severe and find that nothing in terms of home remedies or over-the-counter medications will relieve it. In the most intractable cases, patients will scratch until pain
caused by excoriation replaces the pruritus. In instances of long-standing duration, patients will often shift from scratching to rubbing since they find they can alleviate some of the itching without causing the pain and tissue damage that arises with excoriation.

In time, a vicious circle of itching followed by scratching, followed by more itching and more scratching, develops. This is termed the “itch-scratch cycle,” and its presence is, I believe, the pathognomonic and defining characteristic of atopic dermatitis and LSC. Sometimes, the patients are conscious of the scratching, and many such individuals continue on with the scratching “because I can’t make myself stop” or “because it feels so good to scratch.” Others are unaware of scratching and tend to think that they scratch very little. This is quite analogous to the personal unawareness that develops with fingernail biting, knuckle cracking, and other such “habit tics.”

Scratching during the daytime primarily occurs after using the toilet, when changing clothes after work, and in the evening when one gets undressed for bed. Scratching almost always also occurs episodically at night during the lighter stages of non-REM sleep, and it is associated with an abnormal increase in the number of partial awakenings (4,5). I have termed this nocturnal scratching the “Penelope phenomenon” based on Homer’s tale of Odysseus (Ulysses) and his wife Penelope (6). When Odysseus tarried for many years on his voyage home from the Trojan War, Penelope was urged to declare him deceased and marry one of her many suitors. She agreed to do so once she had completed weaving a funeral shroud for her dying father-in-law. During the day, she wove the shroud, but at night when everyone was sleeping, she would undo most of the previous day’s weaving. The Penelope phenomenon thus represents the nighttime scratching that undoes the benefits of a good daytime therapeutic program.

As indicated above, LSC shares the morphologic characteristics of all eczematous diseases. This includes erythematous, poorly marginated, scaling papules and plaques with evidence of epithelial disruption and/or lichenification (Figs. 6.1, 6.2, 6.3, 6.4 and 6.5). But in contrast to other eczematous diseases, the severity of excoriation and/or lichenification often allows for correct clinical identification. This may not be true in mild cases because the warm, moist environment of the anogenital area may obscure some of the characteristic morphologic features. First, scale may not be as visibly apparent (though it can still be recognized by roughness on palpation) as it is with LSC in other locations (Figs. 6.6 and 6.7). Second, scale is

hydrophilic and when it takes up water it whitens. This white color can be fairly prominent when a patient first undresses but decreases as evaporation reduces the moisture content (Fig. 6.8). Third, deep scratching may destroy or remove melanocytes, leaving hypopigmented areas when the scratch marks heal (Figs. 6.9 and 6.10). Fourth, the anogenital area pigments easily. When LSC has been
present for a long time, postinflammatory hyperpigmentation often develops. This can decrease the apparentness of erythema, leading one to underestimate the amount of inflammation that is present (Figs. 6.11 and 6.12). This is especially likely in patients with naturally dark skin. Genital LSC in women primarily occurs on the outer aspects of the labia majora though involvement of the labia minora is sometimes seen. In men, the scrotum is the predominant site of involvement, but the base or even the entire shaft of the penis is sometimes affected. Perianal LSC in common in both genders (Fig. 6.13).

As mentioned previously, heat and sweat act as provoking factors for the development of both itching and inflammation. Removing or reducing these factors is certainly desirable but is more difficult to do than one might expect. Immediate steps include a change to less occlusive, tight-fitting clothing and the use of materials (such as cotton and cotton blends) that allow for better movement of air. Contrary to decades of physician recommendations, the avoidance of dyes in underwear (“use white underwear only!”) lacks any scientific merit. Other environmental approaches to reduce sweat retention and its consequent contribution to maceration include the avoidance of prolonged sitting, the use of cloth rather than vinyl for seating surfaces, and the use of cooler temperatures in the workspace or home. Weight loss can help those who are particularly obese by way of decreasing intertriginous surface area and reducing frictional rubbing. Note that the use of hair dryers, even on their lowest temperature settings, in an attempt to dry the area is not helpful and in most instances is detrimental.

Other contact irritants include fecal contamination and, for women, the chronic presence of urine and vaginal secretions. Discussion of approaches to fecal and urinary incontinence is outside the scope of this chapter, but additional medical consultation will probably be necessary for ameliorating these two factors. Vaginal discharge needs to be properly diagnosed and treated (see Chapter 15). The regular use of panty liners should be discouraged. Excess hygiene, by way of removing natural skin lubricants, can also be irritating. Asking the patient about the frequency and nature of anogenital hygiene is important because many patients, especially women, think of the anogenital area as a site that is “especially dirty.” Again, contrary to popular opinion, laundering practices for underwear (number of rinses, use of certain detergents, use of antistatic dryer strips, etc.) are for practical purposes never an important triggering factor.

Barrier layer function is never intact in patients with atopic dermatitis and LSC. This dysfunction occurs as a result of genetic factors interfering with epithelial cell differentiation, the irritant factors mentioned above, and the physical disruption of the surface epithelium due to scratching and rubbing. The approach to all three of these factors involves the use of lubrication. Since lubricants are covered in detail in Chapter 3, this material will not be repeated here. Irritants can be dealt with as described in the preceding two paragraphs, and the reduction of scratching is covered below.

Steroids, used topically or systemically, are the sine qua non for the treatment of inflammation. This subject is covered in Chapter 3 in the section “Anti-inflammatory Therapy” and, other than discussion of a few important principles, will not be repeated here. First, the strength of the topical steroid must be appropriate for the task at hand. Low- and mid-potency steroids such as hydrocortisone and triamcinolone are usually ineffective in adults. Second, an ointment vehicle, rather than a cream, will be better tolerated and adds a bit of lubrication. Third, topical steroids must be continued for a month or more after the clinical symptoms and signs have regressed. However, after clinical clearing, the frequency of application or the strength of the topical steroid may appropriately be tapered. This long duration of therapy is necessary because microscopic evidence of inflammation remains for a considerable period of time after apparently complete clinical improvement is noted. Fourth, if topical steroids have not been effective after a month of treatment, the use of systemic steroid therapy should be considered. While a “burst” of prednisone can work, it is usually too short to be maximally effective, and, in addition, rebound
often occurs shortly after the last pills are administered. For this reason, we advocate for the use of intramuscularly administered triamcinolone (Kenalog) as described in Chapter 3. The use of nonsteroidal calcineurin inhibitors tacrolimus and pimecrolimus in an attempt to reduce the side effects of prolonged steroid use may be considered, but the stinging on application and an efficacy less than mid- and high-potency represent significant limitations (12). The use of systemic anti-inflammatory therapy, other than the systemic steroids mentioned above, falls outside the scope of this book. Nevertheless, I would be remiss if I failed to mention dupilumab, which blocks IL-4 and IL-13 signaling. In clinical trials, it has shown remarkable efficacy and quite acceptable safety and likely will achieve FDA approval by the time this book is published (13).

This is the single most important aspect in the treatment of LSC. Unfortunately, it is also the most often overlooked. The presence of clothing, a conscious attempt to control scratching, and embarrassment over scratching the genitalia prevents much daytime scratching. However, these constraints are generally not present at night and thus do not prevent the nighttime scratching that characteristically is present. Approaches for the treatment of nighttime rubbing and scratching are thoroughly covered in Chapter 3, but several major principles will be reviewed here. First, nighttime scratching occurs periodically while the patient is in the lighter stages of sleep (4,14). Nonhabituating medications with a sedative effect such as the first generation of antihistamines and certain tricyclics work well for this purpose. Second, the dose of the medication chosen should be increased until nighttime scratching ceases or until the risks of side effects caution against any further increase. Third, the medication should be taken about 2 hours before the expected hour of sleep. This results in the rapid onset of sleep shortly after the patient goes to bed and greatly helps to prevent morning “hangover.” Fourth, the medication should be taken every evening rather than on an “as necessary” basis.

In many instances, sedating therapy for nighttime scratching obviates the need to treat daytime itching with medications, such as hydroxyzine, that can cause sleepiness or dangerous operation of machinery. However, some patients will still experience significant daytime pruritus. Many clinicians prescribe nonsedating antihistamines for these individuals. Unfortunately, this approach does not work well probably because histamine plays only a minor role in the itching associated with atopic dermatitis and LSC. In this situation, I prefer the use of selective serotonin reuptake inhibitors (SSRIs). It is not clear whether these agents work because of their beneficial effect on anxiety and depression or whether they diminish the obsessive-compulsive component of chronic scratching. While I strongly support this use of SSRIs, there is only limited support for this approach in the medical literature (15). Further information on the use of SSRIs can be found in Chapter 3.

Anxiety and/or depression is regularly present in patients with LSC (9). Most patients will not volunteer this information unless it is directly sought by a clinician. Even then, the importance of psychological factors tends to be minimized by patients, and thus questioning in this area should occur not just initially but also periodically at the time of return visits. Some controversy exists as to whether these psychological factors play a role in the etiology of the LSC or whether they occur secondary to the presence of LSC. It is my opinion, supported by some published data, that they are frequently important in causation (9). But, either way, once identified, treatment, most often with SSRIs as described in Chapter 3, is very helpful.

In addition to the common problems of anxiety and depression, patients with eczematous disease such as LSC may also experience sexual dysfunction (16). Although most of us would not consider ourselves as expert in the area of sexual counseling, giving patients an opportunity to discuss this aspect of their lives can also be quite beneficial in the treatment of patients with anogenital LSC.