Red-brown spots may also be seen. Nail pitting may also occur in alopecia areata . Dermatitis may cause scaling and ridging of the nail plate. Longitudinal grooves and thinning of the nail plate may result from lichen planus. Ingrown nails are caused by sharp lateral corners of the nail piercing the skin leading to inflammation, infection, pain, swelling, erythema , and exudation.
Ingrown nails can result from trauma or poor trimming habits.
The nails are often brittle. Koilonychia may also be a normal inherited condition and is a normal varient in children. Beau lines are transverse, often white, ridges caused by systemic diseases such as high fever, shock or myocardial infarction that result in decreased cell division causing a thin nail plate. Nail growth returns to normal with the resolution of the systemic cause. Clubbing, or an exaggerated curve of the nail plate, can be a sign of congenital heart disease in children and in adults may be associated with cardiac , gastrointestinal and especially pulmonary disease.