Dude my best advice is that your scalp is skin, and even more, it’s skin with a highly concentrated very active quantity of sebaceous glands at that. There’s a lot of different factors that could be coming into play here. But let’s get one thing straight— the vast majority of trichologists don’t advise going long stretches of time like this without washing your hair. Because washing your hair really means washing your scalp. Dry shampoo is a product, like concealer is a product. We all know it would be bad for your skin if you were to put concealer on and not wash it off for five days. That’s why we use make up removers. That is why we cleanse our faces. You can’t just keep slapping things onto the scalp and not remove them. They are mixing with your sebum, things you encounter during the day like pollution and dust, and dead skin cells. Your scalp has pores, and leaving a bunch of muck on it for a prolonged period of time is going to increase your chances of clogging those pores. A clogged pore is going to have a high chance of becoming infected, much like a pimple can, and then getting inflamed.

So, first thing’s first, your goal shouldn’t be to wash your scalp as little as possible. Obviously, there are variations as to how often you might want to wash it based on hair type, texture, and the amount of oil you naturally produce. But I mean, just rub your fingertips on your scalp and smell them. If they stink, your scalp needs to be washed. There are shampoos out there gentle enough to be used everyday, and frankly a lot of people with thin hair benefit from washing that often because it gives them more volume. If your ends are dry, boycotting washes isn’t going to make a huge difference. Maybe a small one. But the oil your scalp secretes really does not travel that much down the hair shaft. You’d be better off focusing on keeping your shampoo on your scalp and not on the ends of your hair, finding an adequate conditioner to apply to the lower parts of your hair, and maybe using a hair oil on the ends in a small quantity.

There’s the chance you might be suffering from an aggressive bacterial colonization of your scalp or even from a fungal infection. It’s not extremely likely, but it’s possible. If you find that keeping up with the removal of product and natural build ups from your scalp isn’t doing anything for your folliculitis, then it’s time to see a dermatologist or trichologist. They can provide you with various medical interventions like topical antibiotics (or oral) and antifungal shampoos.

I once had folliculitis on my scalp, too. It went away once I started paying more attention to adequate cleansing and care of my scalp. My hair is not super brittle or dry— and I wash it every 1-2 days. I have thin wavy hair. The cultural obsession with “no-poo” isn’t backed by much hard science. I have not found significant scientific evidence or studies that support the idea that the scalp is self cleaning or automatically adjusts its sebum output in response to cleansing. The only thing I can think of that might be similar is that dehydrated, damaged, or unbalanced acid mantles/barriers of the skin might produce more sebum to try and restore the proper ph.