Why is Mylanta effective in treating symptoms experienced with
mosquito bites and what are the ingredients that makes it effective.

Hi Becky1217 - 

I was intrigued by your question.  I had never heard of Mylanta as an
anti-itch medication.  But to find out what it was in Mylanta that
soothed bites, I looked up the ingredients.  I found that Mylanta
contains aluminum hydroxide, magnesium hydroxide, and simethicone.

Generic Name  Mylanta
http://www.neonatology.org/ref/meds/med72.html

Next I went to the search site of the National Library of Medicine and
did a search of each of these ingredients with relation to itching
and/or mosquito bites.

Pub Med
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=Index&DB=PubMed

From these searches it was clear that the ingredients of Mylanta are
not recognized as soothing or removing the symptoms of mosquito bites.
 There seems to be no scientific evidenceto explain why Mylanta helps
the symptoms of a bite.

On the non-scientific side, I did find personal testimony as to the
effectiveness of Mylanta for bites.

Open Roads Forum  Family Camping  MYLANTA FOR BUG BITES
http://www.woodalls.com/forums/index.cfm/fuseaction/thread/CFB/1/Tid/304231/DoOnePage/Yes.cfm

A search on Medline on "itching" produced a number of home care
measures to combat itching. These included "Take lukewarm baths using
little soap and rinsing thoroughly. Try a skin-soothing oatmeal or
cornstarch bath.Apply a soothing lotion after bathing to soften and
cool the skin.Apply cold compresses to an itchy area." and "Try
over-the-counter oral antihistamines such as diphenhydramine
(Benadryl).
Try over-the-counter hydrocortisone cream."  None of these measures
mentioned Mylanta or any of its constituent ingredients.

Medical Encyclopedia Itching
http://www.nlm.nih.gov/medlineplus/ency/article/003217.htm#homeCare

I can only conclude that Mylanta for mosquito is either a medical
mystery or it is folk medicine that has not yet been recognized by the
medical establishment.

It may however act like a "soothing lotion" as mentioned by Medline.

Even if you don't know why Mylanta may combat symptoms, if it works,
don't fix it!

Best regards,
Alanna