Decubitus Ulcer Preventation Mattress - Lumex AltaDyne Alternating Pressure Low Air Loss Mattress System

https://www.healthdirect.gov.au/duodenal-ulcer

It depends on where your ulcer is situated eg mouth or stomach.

Take here to the doctor, we are not a medical advice website.

hi Richard.
Brown recluse spider bite The pain associated with a brown recluse spider bite typically increases during the first eight hours after the bite. You may also have fever, chills and body aches. The bite usually heals on its own in about a week. In a minority of cases, the skin at the center of the bite can become dark blue or purple and then evolve into a deep open sore (ulcer) that enlarges as the surrounding skin dies. The ulcer usually stops growing within 10 days after the bite, but full healing can take months.
Seek prompt medical care in the following situations:

• You are unsure whether the bite was from a poisonous spider.
• The person who was bitten experiences severe pain, abdominal cramping or a growing ulcer at the bite site.
• The person who was bitten is having problems breathing.

Your doctor may recommend a tetanus booster shot if you haven't had one in the last five years.
or read up more at this link.

Spider bites Symptoms and causes Mayo Clinic

The first reason to have a mattress protector is to keep your bed clean. Our bodies are not as clean as we think even though we take bath every day. we perspire at night, our skin produces oil while some of us put on makeup. All this can get into the mattress and once it gets in, we cannot remove it. A mattress protector will not let this happen.
Secondly, we all love to keep our mattress new. we do not want it to shorten the life of the mattress. Dust mites consume dead skin cells and the dead skin cells will remain on your mattress if you do not use a mattress protector.
http://bestmattress.in/top-10-mattress-protectors-in-india/

It may be necessary to use a compounding pharmacy to use a anti-bacterial that will treat the ulcer. If he has been to a specialist I assume that the ulcer has been cultured and tested for susceptibility. If the proper antibiotics are being administered then a typical corneal ulcer should heal.
If the ulcer has been cultured and treated accordingly then there are other factors that are causing the ulcer. There is a possibility of the problem being caused by the Herpes Simplex virus or Ocular Cicatrical Pemphagoid.
Have your son see a corneal specialist, if that isn't one of the specialists he has seen. To give you a better answer I would need a fuller picture of the previous diagnosis's, cause of the ulcer and treatments that have been attempted already. Good luck with your son. I hope this helps.