Café au lait is mainly found in certain diseases, such as neurofibroma, of which café au lait is only one of the clinical manifestations. Café au lait is distinguished from cafe au lait by the morphology of the spots and whether they are accompanied by other symptoms. Cafe au lait spots appear at birth or shortly after birth, the number is small, the patches are mostly coffee-colored, the border is clear, the surface is smooth, the area increases proportionally with age, and no longer changes after adulthood. If cafe-au-lait spots are one of the clinical manifestations of neurofibroma, the number of cafe-au-lait spots is more and more, the area is larger, generally there are at least 6 cafe-au-lait spots with diameter more than 1.5 cm, and the whole body is widespread in serious cases. In addition, patients with neurofibroma can show subcutaneous lumps or nodules in addition to cafe-au-lait spots, or various benign and malignant tumors in other parts of the body, and some of the patients have symptoms of developmental delay, mental retardation, epilepsy and so on. Babies born with coffee spots should go to the dermatology department of the hospital in time for treatment; patients with a clear diagnosis of neurofibroma and other diseases should go to the genetic disease clinic for consultation before pregnancy, and do genetic testing if necessary.