Diagnostic Essentials
1. Snake-Head Boil
Initially, it is felt numb, itching and painful in the tip of the finger, and progressively it is felt burning painful, with red color and tumefaction in some cases and no obvious red color and tumefaction in some cases. Afterward, the tumefaction increases gradually and presents in a shape of snake head on the tip of the finger, accompanied by serious throbbing pain and aggravated pain in dropping the infected limb. Pus is formed in about 1- 2 weeks. Work and sleep are often influenced due to serious pain. If the boil is not incised in time, it can cause necrosis of the ungual phalanx. It can be accompanied by obvious general symptoms.

2. Snake-Eye Boil
Initially, it is mostly located on the proximal part of one side of the finger (toe) nail, with slightly red color, swelling and pain. Usually, pus is formed in 2 - 3 days. If it is not treated promptly, the tumefaction can spread to the opposite side to cause peripheral inflammation of the finger (toe) (called nail-border boil in Chinese medicine). If pus invades the subungual area, it can lead to subungual abscess, manifested by yellowish or grey shadow of pus accumulation on the finger (toe) nail, and causing erosive cavity in nail and protruding pterygium of the finger (toe) nail, and even drop of the finger (toe) nail.

3. Snake-Belly Boil
The infected finger swells like a small carrot, manifested by reddened and shining skin and slight flexion of the joint, and pain aggravated severely by any extension of the finger. Pus is formed in about 7 - 10 days. Because the skin in the finger pad is thick and usually is not easy to break in ulceration, if not treated promptly, it can damage tendons. It can be accompanied by obvious general symptoms.

4. Salver Boil
The whole palm is bulged with tumefaction and loses its normal physiological concave, like a salver. In suppuration, the tumefaction and pain are usually more obvious on the dorsum of the hand, and even involve the forearm with serious pain. Pus is formed m about two weeks. Because of the tough skin of the palm, abscess is difficult to break outward and is easy to damage the tendon and bone, and even cause general suppurative infection.

5. Sole Boil
Initially, it feels pain in the sole and difficult to walk, and the infected area feels hard. After 5 - 7 days, a throbbing pain can appear. After the local old skin is cut off, it is possible to see abscess. In severe cases, the tumefaction can involve the whole dorsum of the foot, causing pain in the calf and difficulty in motion. It can be accompanied by obvious general symptoms. In the laboratory examination, the total account of peripheral leukocyte and neutrophil cell ratio in this disease are obviously elevated.