Anyone can get skin cancer, although some people are at greater risk than others. The skin phototype (SPT) system was developed to identify people who are prone to develop skin cancer. The SPT system is a six-point scale based on a person’s skin color and ability to tan (Table 49-1). Individuals who fall into SPT groups I and II are at highest risk for the development of skin cancer. These two groups of people are especially prone to develop basal cell and squamous cell carcinoma and are at high risk for developing melanoma. Skin types III and IV are less prone to develop basal cell and squamous cell carcinoma but are still at risk for developing melanoma. Basal cell carcinoma, squamous cell carcinoma, and melanoma are rare in skin types V and VI. If patients in groups V and VI develop melanoma, it usually occurs on the palms and soles (acrolentiginous melanoma) or on mucosal surfaces, such as in the mouth or on the genitalia.

Table 49-1. Human Skin Phototypes
	SKIN PHOTOTYPE *		UNEXPOSED SKIN COLOR		SUN RESPONSE HISTORY
	I		White		Always burns, never tans
	II		White		Always burns, tans minimally
	III		White		Burns minimally, tans gradually and uniformly
	IV		Light brown		Burns minimally, always tans well
	V		brown		Rarely burns, tans darkly
	VI		Dark brown		Never burns, tans darkly
	* Based on the first 30 to 60 minutes of sun exposure of untanned skin after the winter season.