This job can make a guy humble.
My 99-year-old patient was suffering, having developed blisters, also called vesicles, all over her lower legs, along with intense itching, redness, swelling, and drainage. After discontinuing every unnecessary medication, I treated the possible allergic reaction with a non-sedating antihistamine and steroids. When she didn’t get better, I reviewed blisters and once again realized how many causes there are for a blister on the skin.
Let’s start with the viral infection Herpes simplex type I, also called fever blisters or cold sores. These large blisters cluster around the face and lips and commonly pop up when the immune system is weakened by a cold.
A very similar viral blister or vesicular condition is called Herpes simplex type II, but this one is sexually transmitted. These blisters happen in the genitalia of men and women and recur in a similar mysterious way as the sister condition of “cold sore.” Anti-herpes medicines do help with both conditions.
Another blister condition Herpes Zoster, or “chicken pox,” also a viral infection and a cousin to Herpes Simplex, presents like a teardrop on a rose petal, or a small vesicle on a red base. Once established zoster can set up shop in a nerve and raise it’s ugly head many years later along the distribution of that nerve with a condition called shingles. It is fortunate that vaccination, for the young or those over 60, prevents or reduces the severity in this often miserable condition.
Blisters happen also from contact dermatitis when, for example, an allergy to nickel, poison ivy, antibiotic ointment develops, and that trigger comes in contact to skin. We also see blisters pop-up when unprotected hands are traumatized by raking the yard, burned by grabbing a hot pot handle, or frost-bitten on an ice-fishing expedition.
A life-threatening blister condition may also occur when a person has an allergic reaction to some medicine, or even an infection, and blisters start spreading over extensive amounts of skin and into mucous membranes. Stopping the culprit medicine and providing urgent medical measures can save a life.
My patient didn’t fit any of these scenarios, however. I realized two other mysterious blistering conditions, called pemphigoid and pemphigus, might explain this, and so I made the brilliant diagnostic move to consult an expert. He biopsied the rash, nailed the diagnosis of pemphigoid, treated and cleared the blisters with just the right medicine, and my patient had relief.
The more I learn, the more I am humbled.
Dr. Rick Holm wrote this Prairie Doc Perspective for “On Call,” a weekly program where medical professionals discuss health concerns for the general public. “On Call” is produced by the Healing Words Foundation in association with the South Dakota State University