F

Fifth Disease

Fifth disease is a common childhood infection causing a "slapped cheek" appearance and a rash. It is also known as Erythema infectiosum. It most commonly affects young children and often occurs in several members of the family or school class. Thirty percent of infected individuals have no symptoms. The child is usually otherwise quite well, but occasionally has a slight fever and headache. The first sign is firm red cheeks, which feel burning hot. A rash follows 1 to 4 days later with a lace or network pattern on the limbs and then the trunk. Although most prominent in the first few days, the rash can persist at least intermittently for up to six weeks.

Fixed Drug Eruption

Fixed drug eruption is an adverse skin reaction to an ingested drug, characterized usually, as a solitary lesion which may burn and sometimes blister. Typically there is a bronze discoloration of the skin.

Flushing

Flushing occurs because the blood vessels in the skin dilate. There are various causes. When flushing is produced by activity of the nerves to the blood vessels it is accompanied by sweating. Agents, which act directly on the blood vessels, cause dry flushing.

Folliculitis

Folliculitis is the name given to a group of skin conditions with inflamed hair follicles. Causes of folliculitis includes, infections, irritation from regrowth of hair, contact reactions, inflammatory skin diseases, and acne variants.

Fungal Infections

These superficial infections are extraodinarily common and are more commonly known as jock itch, ringworm, or athlete's foot. They are caused by dermatophytes which are fungal organisms that live off the dead top layer of the skin (stratum corneun, nails and hair). These are usually treated with topical creams unless they are extensive or involve the hair or nails then requiring oral antibiotics for months.