Reddit mentions of Glytone Exfoliating Body Lotion with 17.5 Free Acid Value Glycolic Acid, Keratosis Pilaris, KP, Smooths Rough & Bumpy Skin, Chicken Skin, Fragrance-Free, 8.4 oz.

I've had KP since I was a kid and am finally getting handle on it in my 30s. My current routine is glycolic lotion twice a day, creams on the affected areas 3-4 times a day, and then physical exfoliation and using zinc or sulfur soap a couple times a week to keep the bumps at bay. But since skincare is YMMV, here's the exhaustive list of almost two decades of treatment, in case some of these other things will work for you!

100% of the items can be purchased via Amazon in the US - it's pretty much the only way I shop.

Beginner Level

If your KP has just appeared, focus on physical+chemical exfoliation and moisturizing. Look for lotions with the following ingredients:

• Glycolic Acid [[Link]] (https://www.amazon.com/GLYTONE-Exfoliating-Body-Lotion-8-4/dp/B002D48QRK/ref=sr_1_7_s_it?s=beauty&ie=UTF8&qid=1493069563&sr=1-7&keywords=glycolic+acid+lotion)
  
• Lactic Acid [[Link]] (https://www.amazon.com/AmLactin-12-Moisturizing-Lotion/dp/B000TTPZQ6/ref=pd_sim_194_9?_encoding=UTF8&pd_rd_i=B000TTPZQ6&pd_rd_r=VMNB4G7XKMTDC8FCCPPW&pd_rd_w=3Hg0d&pd_rd_wg=6JKTf&psc=1&refRID=VMNB4G7XKMTDC8FCCPPW)
  
• Mandelic Acid [[Link]] (https://www.amazon.com/Dr-Wu-4712052501942-Intensive-Renewal/dp/B00KQYJ9TI/ref=sr_1_4_s_it?s=beauty&ie=UTF8&qid=1493069480&sr=1-4&keywords=mandelic+acid+serum)
  
• Azelaic Acid [[Link]] (https://www.amazon.com/gp/product/B00MSSJP9Y/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• Salicylic Acid [[Link]] (https://www.amazon.com/Paulas-Choice-Weightless-Treatment-Antioxidants/dp/B00CS5U172/ref=sr_1_7_s_it?s=beauty&ie=UTF8&qid=1493069348&sr=1-7&keywords=paulas+choice+bha) (Or just use [Stridex Pads] (https://www.amazon.com/Stri-dex-Pads-Maximum-Strength-Pack/dp/B004WP0S74/ref=sr_1_1_s_it?s=beauty&ie=UTF8&qid=1493069393&sr=1-1&keywords=stridex&th=1))
  
• Retinol [[Link]] (https://www.amazon.com/Retinol-Surge-Moisturizer-Cream-2-5/dp/B00OQQLNG4/ref=sr_1_1_a_it?ie=UTF8&qid=1493070177&sr=8-1&keywords=body+merry+retinol)
  
• Urea [[Link]] (https://www.amazon.com/Eucerin-Skin-Intensive-Treatment-Lotion/dp/B0098YQH2O/ref=sr_1_1_s_it?s=beauty&ie=UTF8&qid=1493069275&sr=1-1&keywords=eucerin+urea)
  
  Paula's Choice and Derma Doctor's KP duty both work well because they combine a few of these, but you can also get Amlactin, Eucerin and Glytone which are more focused on a single ingredient. Nearly all of the Eucering, Gold Bond, Cetaphil, etc. creams that work have one of the above ingredients, so take a look at the back of the bottle or on CosDna to figure out what works best for you. Prescription creams include Carmol 40 and Ammonium Lactate in higher concentrations.
  
  Physical exfoliation includes:
  
  
• Salux cloths [[Link]] (https://www.amazon.com/Salux-Nylon-Japanese-Beauty-Yellow/dp/B007IAE5WY/ref=sr_1_2_s_it?s=beauty&ie=UTF8&qid=1493068965&sr=1-2&keywords=italy+towels)
  
• Italy towels [[Link]] (https://www.amazon.com/gp/product/B004C8DR1U/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• Hammam or Kessa mitts [[Link]] (https://www.amazon.com/Zakias-Morocco-Kessa-Hammam-Exfoliating/dp/B0076YIPZU/ref=pd_sim_194_3?_encoding=UTF8&pd_rd_i=B0076YIPZU&pd_rd_r=XC3PKNKFAM2Z88K10WDT&pd_rd_w=M6c0H&pd_rd_wg=fsKqw&psc=1&refRID=XC3PKNKFAM2Z88K10WDT)
  
• Dry brushing [[Link]] (https://www.amazon.com/gp/product/B01DHHJ9S6/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• Sugar scrubs [[Link]] (https://www.amazon.com/Tree-Hut-Sugar-Scrub-Moroccan/dp/B01EXDOQZY/ref=sr_1_2?s=beauty&ie=UTF8&qid=1493069250&sr=1-2-spons&keywords=sugar+scrub&psc=1)
  
• Salt scrubs [[Link]] (https://www.amazon.com/gp/product/B01F7WA2X0/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• St. Ives wash [[Link]] (https://www.amazon.com/gp/product/B00J4YY4DM/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• Lush Buffy Scrub [[Link]] (http://www.lushusa.com/body/body-butters/buffy/02127.html)
  
  My dermatologist also recommended moisturizing CONSTANTLY, which really helped smoothe my arms. According to his instructions, "constantly" meant that I needed to be able to feel the lotion on my skin 24/7 for at least 3 weeks, which for me meant a new layer of cream every hour or two. Pretty much any moisturizing lotion or cream will do. I'm partial to [CeraVe Moisturizing Cream] (https://www.amazon.com/gp/product/B013GDK3SQ/ref=oh_aui_search_detailpage?ie=UTF8&psc=1) (creams are less watered down than lotions, and this one drys down wonderfully, leaveing my skin feeling buttery but not sticky). Lush dream cream and Aveeno are also faves.
  
  Intermediate Level
  
  If a bit of exfoliation and moisture aren't working, you might want to consider if there are other skin conditions making your KP worse. For example, it turned out for me I had some fungal skin issues that made my KP bumps more inflamed. Topical steroids can help, but use with care as they can cause skin thinning. Try adding something with the following ingredients in to see if any of the following work. Also talk with your derm about getting a mild prescription treatment that might include an antibacterial or steroid component.
  
  
• Sulfur (typically sulfur soap, although you can also buy some creams) [[Link]] (https://www.amazon.com/gp/product/B00685KUGA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• 2% Pyrithione Zinc (ZnP) (In [soap] (https://www.amazon.com/gp/product/B00MWB0ZGE/ref=oh_aui_search_detailpage?ie=UTF8&th=1) or [cream] (https://www.amazon.com/gp/product/B00N434AWO/ref=oh_aui_search_detailpage?ie=UTF8&psc=1) form)
  
• Tea tree oil [[Link]] (https://www.amazon.com/gp/product/B017L8ZUJE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
  
• Clotrimazole [[Link]] (https://www.amazon.com/Family-Care-Clotrimazole-Anti-Fungal-Cream/dp/B01K51YPCC/ref=sr_1_1_s_it?s=beauty&ie=UTF8&qid=1493069707&sr=1-1&keywords=clotrimazole)
  
• Hydrocortisone [[Link]] (https://www.amazon.com/Cortizone-Cream-Maximum-Strength-Anti-Itch/dp/B001AZTD52/ref=sr_1_1_s_it?s=beauty&ie=UTF8&qid=1493069776&sr=1-1&keywords=hydrocortisone)
  
  As others have mentioned, sunlight also helps. Either give yourself 15 minutes of sun a day or look into UV treatments.
  
  Finally, consider dietary factors – for me cutting out dairy, sugar, and gluten when I really want crystal clear skin makes a big difference. Adding healthy oils and fats to your diet can also improve skin quality.
  
  Advanced Level
  
  I not only have KP, but years of scarring and redness (Post Inflammatory Erythema, or PIE) from picking at the bumps when I was younger. Laser treatments have almost 100% gotten rid of this and made my arms the smoothest and clearest they've been in almost two decades. However, these are pricey (for me, ~$200 a treatment and it took 4) and a serious time commitment. But if nothing else works, consider it.
  
  Other Tips
  
  
• If you pick, use a hydrocolloid bandage right away to make things heal faster.
  
• Vitamin C, niacinamide, honey/propolis, rosehip oil/rosewater, and all those other things this sub and /r/AsianBeauty love can really help reduce redness.
  
• Avoid overly hot showers, as this can be dehydrating. On the other hand, drink lots of water to hydrate internally.
  
• There are a ton of home/natural remedies out there, including using apple cider vinegar and coconut oil, none of which worked for me. These are seriously YMMV. Apple cider vinegar is low Ph, so if that helps, try using a [low Ph cleanser] (https://www.amazon.com/CeraVe-Foaming-Facial-Cleanser-Ounce/dp/B01N1LL62W/ref=sr_1_2_s_it?s=beauty&ie=UTF8&qid=1493070492&sr=1-2&keywords=cerave+foaming+facial+cleanser) or [Ph adjusting toner] (https://www.amazon.com/MIZON-Daily-Clean-Toner-Fluid/dp/B00LUU42NU/ref=sr_1_1_s_it?s=beauty&ie=UTF8&qid=1493070538&sr=1-1&keywords=ph+adjusting+toner), which might be less harsh. Similarly, coconut oil is antimicrobial and moisturizing, so give it a try and if it works, investigate whether you need more moisture or antibacterial/antifungal ingredients in your other products.
  
• Last but not least, don't sweat it! KP is incredibly common and nothing to worry about. I spent years being super paranoid about my arms and keeping them covered up, only to discover none of my friends even noticed my skin or cared at all.
  

I'm just going to echo the other responses here in that topical products need to be applied to the area you want it to work on. There are systemic medications where passing through the epidermal barrier is an effective ROA, but topical skincare is a whole different ballgame. You can check out the usage instructions, which often include "apply to the affected area" (such as this one for hydroquinone).

If you're interested in learning more about how hyperpigmentation treatments work, Topical Hypopigmenting Agents for Pigmentary Disorders and Their Mechanisms of Action is quite good! It doesn't really get into the 'it needs to be applied where you want it to work' thing, but it does get into the various mechanisms of action for hyperpigmentation treatments.

If you're looking for more info on fading a tan, check out How to fade a tan.

It can be hard to find products large enough for body use, and I'm not sure about vitamin C specifically, but here are some recommendations for alternative treatments:

AHAs:

• Alpha Skin Care 12% Glycolic Body Lotion (12oz)
  
  
• Glytone 17.5% Glycolic Lotion (8.4oz)
  
  
• AmLactin 12% Lactic Acid Lotion (20oz)
  
  
• Acne.org's 10% Glycolic Acid (6 or 16oz)
  
  
• The Ordinary 7% Glycolic Acid Toner (240ml/~8oz)
  
  Arbutin
  
  
• Hada Labo Shirojyun Albutin Medicinal Whitening Lotion (150ml/~5oz)
  
  Azelaic acid
  
  
• The Ordinary 10% Azelaic Acid Suspension (only 30ml/1oz, but cheap enough to stock up on)
  
  
• Melazepam (only 60ml/2oz)
  
  Retinoids
  
  
• Paula's Choice Resist Retinol Body Treatment (0.1% retinol) (4oz)
  
  
• Deciem Retin-Oil (hydroxypinacolone retinoate) (100ml/~3.4oz)

There's a pretty easy way to avoid this:

1. Take a warm bath with some bath salts. After about 10 minutes of soaking or so, exfoliate your skin, try this: (http://www.amazon.com/gp/product/B001POYT16/ref=oh_details_o03_s00_i01?ie=UTF8&psc=1) That's just an example, you can get some epsom salt (same stuff) at Walmart for half the price.
   
   
2. Exfoliating the skin first prevents ingrown hairs. Super important. The first time I did this, I did not know how to shave my body properly and I ended up being way too vigorous and getting lots of nasty razor bumps. To exfoliate I used:
   
   
3. Loofah or Pouf (http://www.amazon.com/gp/product/B001CTQMIC/ref=oh_details_o02_s01_i00?ie=UTF8&psc=1) again check Walmart, it'll be cheaper. The main idea here is that you want to exfoliate dead skin and loosen up any hairs that are growing.
   
   
4. St. Ives Exfoliating Body Wash (http://www.amazon.com/gp/product/B004JLGC12/ref=oh_details_o02_s00_i01?ie=UTF8&psc=1) This is a really great natural exfoliant that you can put on the loofah/poof while you scrub
   
   
5. After exfoliation, you shave. I shave against the grain with a good Gillette razor using this shaving cream: Cremo Cream (http://www.amazon.com/Cremo-Astonishingly-Superior-Shaving-Creams/dp/B003FVWRCK/ref=pd_sbs_hpc_3?ie=UTF8&refRID=191FPDNMEKJB5PRZXF94) Which does a really tremendous job. You only need to spread a little bit of it around and it helps to give a really great shave without any irritation (great for both men and women). Plus it last a long time.
   
   
6. Moisturize with your favorite skincare lotion, brand doesn't really matter. You just want to keep that area moist and healthy.
   
   
7. LAST STEP. Most important, DO NOT DO THIS THE SAME DAY YOU SHAVE. DO IT EITHER A COUPLE DAYS BEFORE OR AFTER. Use an acid-based lotion like this: http://www.amazon.com/gp/product/B000TTPZQ6/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1 or http://www.amazon.com/gp/product/B002D48QRK/ref=oh_details_o06_s00_i01?ie=UTF8&psc=1
   The basic idea here is that through chemical exfoliation they'll smooth the red bumps and give you a very smooth look.
   
   
   This is my skincare routine and I don't get any of those ingrown hairs or razor bumps. I used too, though. That's why I do this.

I developed Keratosis Pilaris on my left arm a few years ago. After a few weeks of applying Glytone it largely has gone away. I highly recommend it.

Earlier this year, my dermatologist recommended Glytone Exfoliating Body Lotion, - he gave me this direct link to the product on Amazon. This stuff is wonderful! At around 27 bucks it's not cheap, but won't break the bank either. I use one or two pumps a couple of times a week on my shoulders and arms and noticed results the first week. Three months on, and have just under half a bottle left. My KP is virtually gone. No joke, my arms look like they did when I was 20, even though I just turned (ahem) 40. Edit: Not sure about the % of AHA, but ingredients are listed as Water (Aqua), Glycolic Acid, Propylene Glycol, Cetearyl Alcohol, Petrolatum, Glycerin, Potassium Hydroxide, PEG-40 Stearate, Allantoin, Propyl Gallate, Tocopheryl Acetate. And no smell.

I can't vouch for it myself but I was JUST reading about this lotion for my eczema (in another post) and everyone in the comments is referring to KP treatment: http://www.amazon.com/Glytone-Body-Lotion-8-4-Ounce-Package/dp/B002D48QRK