Ask the Sioux City doc: Get the answers on leather allergies, decoding sunscreen, melanomas and more

In theory, the body can be allergic to anything including leather, soaps, metals, and even the sun! Without actually seeing the rash, it is hard to tell if it was an allergy to the leather or perhaps a rash from something else. Generally if you have an allergy to something, you tend to break out in a rash or have an allergic reaction every time you come in contact with that allergen. So, if you want to experiment to see if you have an allergy to leather, you could sit in the chair again with your skin touching the leather and see if a rash or some irritation develops where your skin was touching the leather.

In that scenario, it would be safe to say that you have a contact allergy to leather. There are varying degrees of reactions to allergens. Some people may just get a stuffy nose, watery eyes and sneeze such as with seasonal allergies.

Another common reaction is breaking out in a rash where your skin came in contact with the allergen. This is commonly noticed with certain metals in earrings, rings, bracelets and belt buckles. The most severe allergic reaction is what we call an anaphylactic reaction in which your airway becomes compromised due to swelling of the lips and throat. This is considered an emergency because without immediate medical attention, anaphylactic reactions can be fatal.

Whenever someone has a known allergy, we as medical professionals advise them to avoid the allergen to the best of their ability to prevent any allergic reactions. When a patient has a known allergy that has caused an anaphylactic reaction in the past, they are highly advised to carry an Epipen with them wherever they go. Without the Epipen, the reaction could be fatal. We also encourage anyone who has a close family member or friend who has an anaphylactic allergy to be familiar with how to administer an Epipen because you never know when your loved one may need your help.

I see so many SPFs in sunscreen. What do they mean? And what I really need?

SPF is an acronym for Sun Protection Factor. This is a relative measure of how long the sunscreen will protect you from ultraviolet rays, specifically UVB rays.

For example, if you tend to burn after 10 minutes in the sun and you apply an SPF 15 sunscreen, this is going to allow you approximately 150 minutes of being in the sun without burning. However, it is important that you apply the proper amount of sunscreen when applying it. It is recommended to apply about one ounce for full body coverage.

The sunscreen also needs to be applied approximately every two hours or sooner while out in the sun, despite the SPF factor. When we swim and/or sweat, some of that sunscreen tends to come off. If you ask a dermatologist what one to use, most are going to suggest an SPF 15 or 30 sunscreen. While sunscreen is important, it is also recommended to wear wide-brimmed hats that will cover the face, ears and back of the neck -- these are some of the most common spots that skin cancers can develop.

Can you get a melanoma on your lip? I think I have a suspicious bump. What should be done about that?

Melanoma can indeed show up on your lips. However, it can also show up in other various parts of the body such as common sun exposed areas, palms, soles and even in the eyes! Yes, even the eyes! When someone noticed a suspicious mole or growths on his or her body, we advise to assess the ABCDE’s.

“A” stands for asymmetry. If you draw a line through the middle of the spot, the two halves will not match, meaning it is asymmetrical. “B” stands for borders. Most benign moles have nice smooth borders. However, most melanomas tend to have an uneven, scalloped or notched border. “C” stands for color. Benign moles tend to be all one color. However, if a mole has various colors including different shades of brown, black or tan, this is a warning sign. “D” stands for diameter. Anything greater than 6 millimeters in diameter or bigger than the eraser on your pencil should be considered suspicious. Lastly, “E” stands for evolving. Most benign moles will remain looking the same over time. However, if a spot evolves or changes in any way, see your doctor. Unfortunately, melanomas that develop in the eye can’t always be detected by the patient themselves. This is why yearly eye exams are important as well.

I noticed some lower back pain while I was sleeping on my back. Is that a sign of anything? Or did I just sleep wrong?

Unfortunately, there are many causes of lower back pain with the most common being muscle strains. However, sleeping on a poor mattress can affect your back and lead to some back pain as well. In theory, when you are lying on your back on a mattress, your spine should be in the proper alignment as it would be if you were standing up straight with a good posture, maintaining the normal curvatures of the upper and lower spine. When mattresses are worn out or well-used, the springs tend to lose their support causing sagging in the mattress and thus can affect your back, causing some pain. An easy way to help prevent your springs in your mattress from wearing out is to rotate and/or flip your mattress every three-to-six months. This way, the same springs aren’t getting overused and your mattress will likely last longer.

My friend’s children have not had vaccinations because she doesn’t believe in them. Should I allow my children to play with hers?

Honestly, there is no right or wrong answer to this question. It is solely going to be based off personal preference and what you feel is going to be safest for your children. In the past few decades, we as a society have relied on herd immunity to help protect those individuals who are not vaccinated. Herd immunity happens when someone who is not vaccinated spends most of his or her time with and surrounded by vaccinated -- also known as "healthy" individuals -- making it less likely to contract any disease or illnesses. However, in today's day and age, with fewer people vaccinating their children and the influx of immigrants who are not vaccinated, herd immunity isn’t as effective and thus, those rare and once-eradicated illnesses are starting to reappear. Everyone has an opinion on this hot topic, so as stated above, you have to do what you feel is going to be safest for you and your children.