Hi, A.. Well, this is a bit unusual as most boys enjoy being dirty in all its forms. If the person who was taking care of him up to this point was too anxious about keeping him clean, then that may be why he is anxios about it, too. I think your instinct to help him get de-sensitized to these things is good, but you have to go about it slowly and gently because he sounds like he has a lot of anxiety about it.
It's a bit early to try to diagnose him with Obsessive Compulsive Disorder. Just because he has relatives with OCD doesn't mean he has to get it. A lot more of OCD is learned behavior than most of us want to believe. Also, folks with OCD are trying to get control and maintain control over their environment, and for some reason, compulsive behaviors make them feel safe. It also gets them attention, and it also gets them a certain amount of respect because ppl cater to their phobias rather than upset them.
It's a rather complex issue, and I want to make it clear that I'm not criticizing anyone who has it or anyone who loves or cares for someone with OCD. However, this disorder is counterproductive to enjoying life or having successful relationships or careers, so I think that if a small child shows a tendency toward this kind of disorder, ppl who love this child should do whatever they can to help him overcome the phobia before it gets so deeply entrenched that it hurts the child's life.
I think that possibly you can substitute hand-washing for clean wipes. That way, the child can wipe his hands clean and not have to run away from the room or the situation. That can help him see that the situation is not frightening and it's a manageable situation.
He may have some anxiety about interacting with other ppl which manifests through fear of touching things or getting dirt on his hands. Quite often, phobias are not even about the things we're afraid of at all! Sometimes our fears get transferred to things that are actually not harmful, because we are actually afraid of things that are much larger, but we are too scared to deal with those fears because they are so much scarier and bigger than we can cope with. So phobias are coping mechanisms, even though they seem so odd and self-destructive.
Anyway, I would try introducing your son to either unscented or pleasant-smelling wipes that take off whatever goop he gets into. Don't use anti-bacterial ones because he could hurt his eyes or put his fingers in his mouth, and that would make him sick. Show him how to wipe his hands himself, and he will feel more in control because he's doing this himself.
I would also try helping him learn to do things that don't involve dirt, mess or stickiness. Throwing a ball, drawing with crayons, taking walks in the park, putting together puzzles, reading, singing, etc., are all good ways to give him positive attention and give him a sense of safety and mastery without touching off the phobia.
I have the feeling that he may outgrow the problem with time and attention to other things besides trying to make him overcome the phobia. You might try getting him to color pictures that help him express how he feels about all kinds of things, and work into pictures of the things that scare him. You can try drawing with him and showing him how you deal with things that you don't like, but start out with the two of you drawing things you like. He may spontaneously draw you what's bothering him without being asked to do so, but if he avoids it, you can draw something you don't like and talk about how you got over it or got past it.
Again, he's a little young to be diagnosed, and kids his age develop all kinds of fears. I started to be afraid of the dark at this age, and because my parents laughed at me and my sisters were allowed to torment me about it, I didn't overcome my fear of the dark until I was close to 40 years old. I was also terrified of spiders, and when I would have nightmares about spiders, I woke up facing two things that terrified me -- spiders and darkness! I didn't overcome my fear of spiders until I got over fear of darkness, and I was about 45 years old. Again, ppl thought it was a good idea to terrorize me with rubber spiders and pictures of tarantulas, and this just drove the fear in deeper.
The root of the fear has to be discovered, and it has to be done gently and lovingly.
You can also try giving him gloves to wear some of the time.
If he doesn't come out of the phobia in a few months, you might want to get him some therapy.
I hope everything works out for his happiness and peace.
Blessings,
Syl