Diary of a Primary School Mum: Head lice alert - and a mystery pain for Oliver

Reception teacher Miss Perry sticks up a sign in the class window. Head lice alert! It has come to our attention... The itch immediately takes grip. I can't stop scratching and pray, when twins Claire and Oliver emerge, that they don't actually have nits.

Sifting through their school bags back at home a bug buster kit tumbles to the floor. Magnified images of the bloodsuckers towers over blurb which explains how to detect the rascals. Instead of lotions and potions it suggests outwitting them by running a teeny tiny comb painstakingly through the hair. The pros (riddance of lice) versus the cons (two screaming five-year-olds with thick, unruly manes) are considered and dismissed. Comeuppance was to come.

A week later, Oliver wakes in the middle of the night. "What is it darling?" "My bottom hurts," he howls. "Where exactly does it hurt?" He points. "A haemorrhoid?" I suggest to my husband. He shakes his head. "I think he's too young for something like that." We ask our son to describe the pain. He winces. "Ooh, ah, no, it feels like there's a big ship in my bottom." An ice-pack seems to do the trick and the next 12 hours or so pass uneventfully. By dusk, the cycle repeats. "Ouch, my bottom really hurts." I administer some medicine and all's well until 10pm.

Ice-packs, words, ibuprofen, my son is inconsolable. Slippers and dressing gowns are donned and we head to the A & E. In the waiting room my son is now quiet and lays his head on my lap. "How are you feeling?" I ask. "Exhausted," he says, "but the pain's gone."

Finally we are seen. "Would you mind me taking a look?" the Doctor asks Oliver, snapping on some latex gloves. My boy dutifully rolls on to his tummy, inhibition free, and I bite my nails. Quicker than the doc can snap the gloves back off, the inspection is over. "Yep, just as I'd thought."

The Doctor looks amused. "What is it?" I whisper. "Worms," she says, "and the reason I know is that one just popped out to say hello." I cover my ears. "How on earth did he get it?" I ask. "At school most likely it's incredibly common. One child has them, doesn't wipe their bottom properly, your son touches something they touch and there you have it."

Turns out the entire family needs to be fumigated inside and out and while a medical tome is consulted to check which medication suits all, my son and I are left alone. "Roll over," I tell Oliver. "I want to take a look." So he does and I do, and I see one, this little gold sliver wriggling around. I want to catch it, only I'm too squeamish and too slow and it slithers back in.

Back at school I wonder if Miss Perry should be informed. When the nits sign went up I scanned the crowd, trying to ascertain which head of hair was responsible for the infestation. As for wondering which bottom... I just couldn't do it.