The word "瘙痒" is formed by combining the characters "瘙" and "痒", both containing the "疒" radical to signal a medical or discomfort-related meaning. "瘙" incorporates "蚤" (flea), which semantically suggests a cause of itching and phonetically approximates "sào", while "痒" uses "羊" primarily for its phonetic role in indicating "yǎng". Together, they create a compound term specifically denoting the condition of itching.