Final answer:
An arciform lesion is a skin lesion with an arc-like or bow-shaped pattern, which can be partially circular or curved. Conditions like ringworm cause itchy, ring-like lesions and can be diagnosed using a Wood's lamp. Different skin conditions and cancers can present varied types of lesions.
Step-by-step explanation:
An arciform lesion is a skin lesion that is characterized by its arch-like or bow-shaped (arc-like) pattern. Rather than presenting as a complete circle or ring, arciform lesions appear as a partial ring or a curved line on the skin. An example of a condition that can cause itchy, ring-like lesions is ringworm, which is a fungal infection that can affect various parts of the body and may present as circular, red, and raised edges similar to the case described with 7-year-old Sarah. Ringworm lesions can be identified using a Wood's lamp, a diagnostic tool that emits ultraviolet light causing some types of fungi to fluoresce. Other skin conditions, such as contact dermatitis or certain types of skin cancer, like basal cell carcinoma, squamous cell carcinoma, and melanoma, may produce various types of skin lesions with different shapes and characteristics.