Hi Anon_23520,
Angular Cheilitis is NOT a sexually transmitted disease. (I will get back to this later in my response).
Although I cannot diagnose you online what you have described does seem to fit into the clinical diagnosis of angular cheilitis.
Before I respond to your question you should be aware that candida is a normal part of your oral flora and is supposed to be in your mouth. It helps keep the bacteria and microorganisms that also live in your mouth in check. Therefore testing to see if you can grow candida on an agar plate is a waste of time and money, of course a culture will show growth of candida, as it is supposed to live in your mouth.
A very very (very) long time ago Angular Cheilitis was thought to be a vitamin deficiency specifically a vitamin b deficiency. However, unless you have a GI disease like Irritable bowel syndrome or an intrinsic factor disorder where you are not absorbing nutrients through your gut, it is virtually impossible to have a vitamin b deficiency in this country as everything is vitamin fortified or enriched.
Oral candidiasis, colloquially referred to as "thrush', is a common fungal infection that may present in both immunocompetent and immuno- compromised patients.
Oral candidiasis may result in pain on swallowing, oral discomfort, localized swelling, bitter or sour taste and loss of function in addition to angular cheilitis.
It is associated with numerous local and systemic conditions including decreased vertical dimension, dry mouth, braces, drooling during sleep, immunosuppression, HIV infection, chemotherapy, poorly controlled diabetes, xerostomia, and denture stomatitis. To name a few.
Chronic Angular Cheilitis: Presents as perioral erythema and/or cracking, fissuring and superficial ulceration at the corners/commissures of the mouth. It can be quite painful if left untreated.
What I can tell you is that regardless of why you have angular cheilitis, the clinical presentation of angular cheilitis is always due to a yeast infection.
Can you get it or give it to a partner during sex. Yes but the much more likely explanation is that you have an over growth of the fungal organisms that are supposed to live in your mouth.
My recommendation is to figure out first if you have an intra oral yeast infection. If you do, treat it with an OTC or prescription anti fungal preparation and most likely the corners of your mouth will improve.
The WORST possible thing to do is apply petroleum jelly to the affected area. Petroleum jelly is hydrophilic it will suck the moisture out of the thin skin of the lips and make the problem much worse and last longer. Vaseline is great for elbows but not the delicate skin of the lips.
So angular cheilitis is a chronic yeast infection. It will go away however dry mouth, dentures, medication, air conditioning, may all affect how quickly you will feel better.
If it continues to bother you I recommend seeing your dentist or physician for a prescription or checking with the pharmacist for an OTC remedy.
I hope this helps!
Dr. Gwen Cohen Brown