Dear Doctors: We recently relocated for my husband's job. It's hotter here and a lot more humid than our previous home. All three of our children, including the baby, are suddenly dealing with heat rash. Why does that happen? How can we help them avoid it?

Dear Reader: It has been a long, hot summer, and we suspect you are not alone in dealing with the unpleasant realities of heat rash. The condition is also sometimes referred to prickly heat, a succinct summary of the symptoms and their root cause. In medical language, it is known as miliaria. These terms all refer to the patches of small, raised bumps that develop when someone's sweat glands and sweat ducts become blocked, often due to heat and humidity. These blockages can occur at the surface of the skin, or deeper within the sweat duct.

When your sweat ducts or glands become blocked, perspiration can't spread out across the surface of the skin. Instead, the moisture backs up within the epidermis. This leads to irritation and inflammation and a constellation of other symptoms. These can include itchiness that can become severe, a persistent prickling or burning sensation and swelling. In pale skin, the bumps of heat rash typically appear as areas of reddening. In darker skin, a change in skin color in the affected area may not be apparent.

The blockage that leads to heat rash is caused by a persistent layer of perspiration, often mixed with the skin's natural oils. It occurs when sweat becomes trapped, often due to high humidity, which prevents adequate evaporation. Babies and young children, whose sweat glands have not yet fully developed, are particularly susceptible to heat rash. So are adults who are overweight or obese, and anyone who is overdressed in hot and humid conditions.

Common sites of the condition include the backs of the knees, beneath the breasts, the armpits, creases of the elbows, neck, inner thighs, back, waist and groin area.

While uncomfortable, heat rash is usually harmless. Treatment focuses on cooling the affected area and keeping it clean. This can be done with a moist cloth or a cool bath or shower.

Dress your children in a single layer of loose-fitting clothing, which helps eliminate friction. Natural fibers, like cotton and linen, are more breathable than synthetics. Shorts and sleeveless tops are helpful. So is proper ventilation. This same approach to preventing heat rash applies to adults, too. When it comes to your baby, do frequent diaper checks, and change it as soon as it is wet or soiled.

Areas of persistent itchiness in someone with heat rash can be soothed with over-the-counter ointments and lotions meant to treat rash.

As with any site of inflammation, infection is possible. This can cause sweat ducts with deeper blockages to develop small pockets of pus. If this occurs, it is important to seek medical help in dealing with the infection. When treated, heat rash goes away in a day or two. If the condition persists or appears to get worse, see your health care provider.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I have seen my doctor and gynecologist for pain in my groin area that gets worse when I'm sitting or if I squat. It worsens at the end of the day. I'm told it could be pudendal neuralgia. I've never heard of that. Can you please explain what that is?

Dear Reader: The term “neuralgia” refers to abnormal sensations that arise in a nerve pathway. They can range from numbness, tingling or burning to pain that is described as sharp, stabbing or like an electrical shock. Some people also become hypersensitive to cold or to touch. When this occurs, something as minor as lightly brushing the skin can result in pain or discomfort.

Causes include inflammation, infection and the effects of certain chronic diseases. Physical pressure on a nerve, or on the tissues or structures adjacent to a nerve, can also cause the condition. That's the case with pudendal neuralgia.

The pudendal nerve originates in a bundle of nerves located at the lower back of the pelvic wall and runs through the pelvic region and buttocks. It is a paired nerve, which means it is present on both sides of the body. The nerve and its branches animate and provide sensation to much of the pelvic region. It is crucial to passing urine and feces, and to sexual sensation and function.

Damage or injury to the nerve can cause the pain and other sensations you have described. It can also interfere with voiding the bowels or bladder, and with sexual function.

The path and location of the pudendal nerve leaves it somewhat vulnerable to injury. This includes from prolonged sitting and activities such as cycling or horseback riding.

Childbirth, during which the nerve is repeatedly stretched, can also play a role. Typically, any symptoms related to the pudendal nerve recede within a few weeks of giving birth. But in some cases, such as during a difficult or prolonged labor, the nerve can become inflamed or even damaged.

Diagnosis of the condition begins with a physical exam, including a vaginal or rectal exam. Scans, such as an MRI, can be helpful in identifying possible points of nerve entrapment. In some instances, a nerve block may be used as a diagnostic aid. This involves disabling the nerve with an injection and then gauging if the symptoms have abated.

Treatment is a mix of behavioral changes, physical therapy and the use of medications to manage pain and inflammation. It's also important to avoid any painful stimuli. In your case, this includes sitting and squatting, and any activities that involve hip flexion. For patients whose pain arises from muscle spasms, physical therapy can be helpful.

Medications to manage nerve pain, including analgesics, muscle relaxants, antidepressants and anticonvulsants, may be prescribed. Studies show that a nerve block that includes an anesthetic plus a corticosteroid can confer pain relief that lasts for up to a month.

When nerve entrapment has been confirmed, surgical decompression may be needed. This now includes several minimally invasive laparoscopic techniques. For a diagnosis, seek out a neurologist familiar with this condition.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I am 65 years old, and I have never been to a cardiologist. I am concerned about heart disease and the possibility that I may have blocked arteries. I would like to know what screenings -- an MRI? an exercise stress test? -- I should get.

Dear Reader: As someone who has not undergone the screenings commonly used to evaluate cardiac health, it's best to start with the basics. These can be done by your regular doctor.

The appointment typically begins with a discussion of your medical history. This includes information about any diseases or conditions for which you are currently being treated, and any in your past that may have a residual effect on general health. Family history, which can suggest a genetic predisposition for certain diseases and conditions, is an important factor, as well.

Your weight, and possibly your BMI, will be recorded, and your doctor will obtain readings for heart rate and blood pressure. Testing will also include a blood lipid profile and a blood glucose level. Taken together, this information offers important insights into health risks that you may face. If the test results suggest a problem beyond the scope of your primary health care provider, such as a heart condition or heart disease, they will refer you to a cardiologist.

When visiting a cardiologist, expect them to review the test results that brought you under their care, and to explain how the results are a factor in the health of your heart. Depending on those results, you may also be asked to undergo additional tests that assess various aspects of cardiovascular health. These can include an EKG, which measures electrical activity in the heart; echocardiography, which uses ultrasound to create moving pictures of the heart; and scans that measure blood flow in the veins or that identify the presence of calcium deposits. A test known as CCTA, or coronary computed tomography angiography, produces 3D images that can help detect abnormalities in blood flow and identify possible blockages. An exercise cardiac stress test measures heart rate and rhythm, blood pressure and electrical activity of the heart as the patient performs increasingly strenuous exercise.

The cardiologist will also discuss specific aspects of your lifestyle. This includes a review of your diet, exercise habits, use of alcohol or tobacco products and your perceived level of stress. You will be asked about medications you are currently taking. It's important to provide the doctor with a complete and accurate list, and to also include any dietary supplements that you may be using. They will also want to know about any family history of heart disease.

Depending on the findings, you may be prescribed medications to manage high blood pressure or high cholesterol. You may also be advised to make lifestyle changes. These can include reaching a healthier weight, exercising more or more frequently, adjusting your diet, moderating the use of alcohol and quitting tobacco products. Your cardiologist will also schedule additional appointments to evaluate the efficacy of your treatment program. For the health of your heart, and your general well-being, it's important that you follow through.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)