Colloquial term for phimosis, literally 'wearing a skin hat'. The more formal medical term is 包茎 (ほうけい).
See also: 包茎 (ほうけい) · 皮かぶり (かわかぶり)
He seems to be troubled by phimosis.
I looked up treatments for phimosis online.
Common colloquial spelling; the かむり part is often written in kana.
Kanji spelling is rare; the word is usually written as 皮かむり or 皮被り.
Compound of 皮 (かわ, 'skin') and かむり (from 被り, 'covering'). The literal meaning 'skin hat' is a colloquial metaphor for phimosis.