My 4 years boy usually swipe his lips with his tongue to make it wet, we live in a dry weather. will it goes by itself, or any concerns are there?

Lip licking: A condition called 'lip lickers dermatitis' is the most likely problem that can result from chronic licking of the lips. It appears as a severe case of chapped lips that extends onto the skin surrounding the mouth. It can be painful and possibly superinfected with a yeast-type infection. It is not dangerous or contagious. Using a moisturizing lip balm can help prevent it.

Yes: you need to help him with a lip moisturizers to keep it moist If he continues it can irritate the lip and skin around his mouth causing a rash which is hard to treat without stopping this habit Set up an award system to help him with the habit and encourage him to stop See a provider if more or gets the rash around the mouth

Lips: Great question. Could be habit, sometimes dehydration or you need a humidifier at night. May come and go. Have him checked out by his doctor as well