While no scarring has been found to be associated with the rash, scratching should be avoided. Its possible that scratching can make itching worse and an itch-scratch cycle may develop with regular scratching (that is, you itch more because you scratch, so you scratch more because you itch, and so on). Irritants such as soaps with fragrances, hot water, wool, and synthetic fabrics should be avoided. Lotions that help stop or prevent itching may be helpful.Direct sunlight makes the lesions resolve more quickly. According to this principle, medical treatment with ultraviolet light has been used to hasten resolution, though studies disagree whether it decreases itching or not. UV therapy is most beneficial in the first week of the eruption.A 2007 meta-analysis concluded that there is insufficient evidence for the effectiveness of most treatments. Oral erythromycin was found to be effective for treating the rash and relieving the itch based on one early trial; however, a later study could not confirm these results. Prognosis
In most patients, the condition lasts only a matter of weeks; in some cases it can last longer (up to six months). The disease resolves completely without long-term effects. In a ten-year epidemiological study of 939 people in the United States, less than two percent had a recurrence. Epidemiology
The overall prevalence of PR in the United States has been estimated to be 0.13% in men and 0.14% in women. It most commonly occurs between the ages of 10 and 35.
Mechanisms include retrograde menstruation resulting in abdomino-pelvic spread, blood-borne or lymphatic spread and deposition, and metaplasia.Thoracic endometriosis is the most common non-abdominal site of involvement and is also the primary risk factor for catamenial pneumothorax. Catamenial pneumothorax is the primary clinical presentation of thoracic endometriosis, and is defined as recurrent episodes of lung collapse within 72 hours before or after menstruation. Signs and symptoms
Symptoms include chest or shoulder pain, cough, dyspnea, and shortness of breath. Chest and shoulder pain can be radiating out to the shoulder blades. A dry cough can also present and come with a "crackling" sound upon inhaling. Typically, it occurs in women aged 30 to 40 years, but it has been diagnosed in young girls as early as 10 years of age and post menopausal women (exclusively in women of menstrual age), most with a history of pelvic endometriosis.Chest pain requires immediate medical attention. Pathophysiology
Although the exact cause is not known, a few theories come from metastatic, hormonal, and anatomical possibilities. The metastatic model proposes that endometrial tissue has migrated from the endometrium to the diaphragm or the pleural space, causing small holes in the diaphragm, allowing air into the pleural space. In the hormonal model, it is believed that prostaglandin F2 causes a narrowing of the bronchioles, the small tubes within the lungs. Narrowing of these can cause the alveoli to rupture which may trap air in the pleural space.