Because newborns have no neck to speak of, the area between the torso and the face can become very sweaty and aggravated. This moist irritation of the skin can also affect other creases or folds, such as the armpits or the area behind the ears. This type of rash is not painful. Some people advise applying cornstarch to dry the affected areas, but I don’t; it’s not particularly effective, and it makes the skin look cake-y. In more impressive forms (where you see extensive redness and moisture), this damp area can be colonized by a fungus, which loves humid places. In that case, apply an antifungal cream such as Lotrimin twice daily until the rash clears. But the definitive treatment is for Lucy to grow a neck. That’ll take a few months.