Chafing occurs when two opposing skin surfaces rub together and are irritated by sweat, as in the armpits, under the breasts and beneath overlapping parts of the belly of fat people, and between the thighs and buttocks. The same result is caused by the irritation induced by discharges constantly running over the skin, as that seen in infants, due to the presence of urine and bowel discharges, and that irritation which arises from saliva when the lips are frequently licked. The latter condition of the lips is commonly called chapping, but it is proper to consider chafing and chapping together as the morbid state of the skin, and the treatment is the same for both.

Chafing occurs more often in hot weather and after violent exercise, as rowing, riding, or running, and is aggravated by the friction of clothing or of tight boots. It may, on the other hand, appear in persons who sit a great deal, owing to constant pressure and friction in one place. The parts are hot, red, and tender, and emit a disagreeable odor when secretions are retained. The skin becomes sodden by retained sweat, and may crack and bleed. The same redness and tenderness are seen in chapping of the face and lips, and cracking of the lips is frequent.

In chafing the first requisite is to remove the cause, and then thoroughly wash the part with soap and water. Then a saturated solution of boric acid in water should be applied with a soft cloth, and the parts dusted with a mixture of boric acid and powdered starch, equal parts, three times daily. If the lips are badly cracked, touching them, once daily, with a stick of silver nitrate (dipped in water) is of service.