CHICAGO – Diagnosing the cause of vaginal itching, which can have a significant negative impact on a woman’s quality of life, can be particularly difficult for multiple reasons, according to Rachel Kornik, MD, of the departments of dermatology and obstetrics and gynecology at the University of Wisconsin, Madison.
“The anatomy is really challenging in this area, and there’s a broad differential. Often there’s more than one thing happening,” Dr. Kornik said during a session on diagnosing and managing genital pruritus in women at the American Academy of Dermatology summer meeting. Like hair loss, vaginal pruritus is also very emotionally distressing.
“Patients are very anxious when they have all this itching,” she said. “It has an impact on personal relationships. Some patients find it difficult to talk about because it’s a taboo subject, so we have to make them comfortable.”
Dr. Kornik showed a chart of the inflammatory, neoplastic, infections, infestations, environmental, neuropathic, and hormonal. But she focused her presentation primarily on the most common causes: contact dermatitis, lichen sclerosus, and lichen simplex chronicus.
Contact dermatitis
The most common factors that contribute to contact dermatitis are friction, hygiene practices, unique body exposures (such as body fluids and menstrual and personal care products), and occlusion/maceration, which facilitates penetration of external agents. Estrogen deficiency may also play a role.
Taking a thorough history from the patient is key to finding out possible causes. Dr. Kornik provided a list of common irritants to consider.
- Hygiene-related irritants, such as frequent washing and the use of soaps, wash cloths, loofahs, wipes, bath oil, bubbles, and water.
- Laundry products, such as fabric softeners or dryer sheets.
- Menstrual products, such as panty liners, pads, and scents or additives for retaining moisture.
- Over-the-counter itch products, such as those containing benzocaine.
- Medications, such as alcohol-based creams and gels, trichloroacetic acid, fluorouracil (Efudex), imiquimod, and topical antifungals.
- Heat-related irritants, such as use of hair dryers and heating pads.
- Body fluids, including urine, feces, menstrual blood, sweat, semen, and excessive discharge.
It’s also important to consider whether there is an allergic cause. “Contact dermatitis and allergic dermatitis can look very similar both clinically and histologically, and patients can even have them both at the same time,” Dr. Kornik said. “So really, patch testing is essential sometimes to identify a true allergic contact dermatitis.”
She cited a study that identified the top five most common allergens as fragrance mixes, balsam of Peru, benzocaine, terconazole, and quaternium-15 (a formaldehyde-releasing preservative) (Dermatitis. 2013 Mar-Apr;24(2):64-72).
“If somebody’s coming into your office and they have vulvar itching for any reason, the No. 1 thing is making sure that they eliminate and not use any products with fragrances,” Dr. Kornik said. “It’s also important to note that over time, industries’ use of preservatives does change, the concentrations change, and so we may see more emerging allergens or different ones over time.”
The causative allergens are rarely consumed orally, but they may be ectopic, such as shampoo or nail polish.
“What I’ve learned over the years in treating patients with vulvar itching is that they don’t always think to tell you about everything they are applying,” Dr. Kornik said. “You have to ask specific questions. Are you using any wipes or using any lubricants? What is the type and brand of menstrual pad you’re using?”
Patients might also think they can eliminate the cause of irritation by changing products, but “there are cross reactants in many preservatives and fragrances in many products, so they might not eliminate exposure, and intermittent exposures can lead to chronic dermatitis,” she pointed out.
One example is wipes: Some women may use them only periodically, such as after a yoga class, and not think of this as a possibility or realize that wipes could perpetuate chronic dermatitis.
Research has also found that it’s very common for patients with allergic contact dermatitis to have a concomitant vulvar diagnosis. In one study, more than half of patients had another condition, the most common of which was lichen sclerosus. Others included simplex chronicus, atopic dermatitis, condyloma acuminatum, psoriasis, and Paget disease.
Therefore, if patients are not responding as expected, it’s important to consider that the condition is multifactorial “and consider allergic contact dermatitis in addition to whatever other underlying dermatosis they have,” Dr. Kornik said.