Our skin is the largest organ that humans have. It serves a number of functions. One of the most important is to keep moisture inside the body and protect the interior of the body from germs. It also is the site of lots of nerve communication that lets us keep track of temperature in the environment and many of the ways that we regulate our temperature on the inside as well as touch, pain, pleasure, movement, and some forms of communication to others. Another important function is to manufacture vitamin D which is becoming better understood in its role to assist with calcium storage and a possible relationship to depression and mood disorders.
Illness within the body, within the skin, and external factors such as temperature, sun, chemicals, and physical damage may interfere with the skins ability to do its multiple jobs. Because it is the part of our body that we can all see, skin problems are often the first clue that something is wrong inside. The following links can give you an idea of some common conditions and when they need medical attention. Do not mistake these for medical recommendations or advice about treating skin or any other condition, that needs a health care professional’s examination and recommendations.
How to tell if a rash needs medical attention.
https://www.aad.org/media/news-releases/how-to-tell-if-a-rash-needs-medical-attention
Boils: Treatment, causes, and symptoms.
http://www.webmd.com/skin-problems-and-treatments/guide/boils#1
Cellulitis:
https://medlineplus.gov/ency/article/000855.htm
Heat Rash/Prickly Heat:
http://patient.info/health/prickly-heatheat-rash-miliaria
Contact Dermatitis:
http://www.mayoclinic.org/diseases-conditions/contact-dermatitis/basics/symptoms/con-20032048