57歲男性因急性鞭打狀皮疹求診，紅條狀皮膚病灶出現於軀幹與下肢，伴隨輕微的癢感，除此之外沒有其他不適症狀與過往病史。發疹的三天前，曾經食用烤香菇，因此診斷為香菇皮膚炎。只有口服抗組織胺以緩解癢感，鞭打狀皮疹在1週後完全復原。鞭打狀皮疹是一種獨特的皮膚病徵，特定之藥物、風濕疾病、或未充分煮熟的香菇都可能造成此種皮疹表現。針對鞭打狀皮疹的鑑別診斷，筆者歸納整理為一流程圖，有助於在診斷香菇皮膚炎前，藉由詳細的病史詢問，排除特定藥物、接觸物質暴露、以及關節炎和肌肉無力等系統性疾病徵狀。

A 57-year-old man had acute onset, mildly pruritic whiplash-shaped erythematous streaks over his trunk and lower limbs. He ate barbecued shiitake mushroom 3 days prior without other discomfort. Shiitake dermatitis (SD) was clinically diagnosed, and complete resolution was achieved 1 week later through treatment with oral antihistamines. Whiplash-shaped flagellate dermatitis is a unique skin manifestation, which may result from a drug reaction, rheumatic disorder, or undercooked mushrooms. Before diagnosing SD, the clinician must exclude other possible causes through comprehensive history taking and laboratory tests. We developed a flowchart for approaching a patient with whiplash rash.