Otitis externa – etiological factors 1. Viral factors: common causative agents are Staphylococcus aureus, Streptococcus, Pseudomonas aeruginosa, and Proteus. 2.Disease factors: Systemic diseases such as diabetes, anemia, endocrine dysfunction, etc. also predispose to this disease. 3. Habitual factors: Softening, swelling, rupture of the epithelium and destruction of the stratum corneum due to swimming or bathing, which can cause infection due to the invasion of pathogenic microorganisms. Otitis externa – Clinical manifestations 1. Burning, itching, pain, diffuse congestion, swelling, epidermal erosion, first plasma discharge, then plasma or purulent discharge in the external auditory canal. The skin is swollen and obscures the eardrum, producing conductive deafness and tinnitus. In severe cases, the peri-auricular lymph nodes are enlarged and generalized fever and discomfort may occur. 2. Redness and ulceration of the ear canal. The common symptoms are external ear canal boils and diffuse otitis externa, which are called ear boils and ear sores respectively in Chinese medicine. The former manifests as limited redness and swelling with obvious pain, protruding like a pepper eye or topped with pus, while the latter is diffuse redness and ulceration with more yellowish-white secretions. In the latter case, there is diffuse redness, swelling, ulceration and more yellowish white discharge. 3. Sometimes removing the scab may cause bleeding, and the tympanic membrane may be cloudy and thickened, or there may be a small amount of granulation on its surface due to damage to the epithelium of the tympanic membrane. 4. Foreign body in the external ear canal. This symptom is mostly seen in children, but can also occur in adults. Most of them are caused by ear digging or traumatic legacy, and insect invasion. Foreign bodies can be divided into non-living, plant and animal types. If the foreign body is small and not irritating, it can remain for a long time without symptoms. Large foreign bodies can block the ear canal and cause hearing loss and a feeling of swelling. Sometimes it causes vertigo, tinnitus and ear pain, or may cause skin breakdown. Otitis externa – Differential Diagnosis It is important to differentiate from other diseases of the external auditory canal such as fungal diseases of the external auditory canal. Severe boils on the posterior wall of the external auditory canal can cause redness and swelling in the posterior sulcus and mastoid area, which should be differentiated from acute mastoiditis. In acute mastoiditis, there is a history of acute or chronic purulent otitis media, fever is more obvious, there is no auricular pulling pain, but pressure pain in the mastoid area; there is tympanic membrane perforation or the tympanic membrane is obviously congested, and there is more pus.
X-rays of the mastoid show cloudy mastoid air spaces or bone destruction. Otitis externa – Treatment 1. Early local heat application or physiotherapy such as ultrashort wave heat transmission; 2. Antibiotics to control infection in severe cases. Take sedative and analgesic; 3. Use 1-3% phenol glycerin or 10% ichthyol glycerin to drip the ear locally, or use the above liquid gauze to put on the affected area, and change the gauze twice a day. For chronic cases, a combination of antibiotics and steroid hormones (such as prednisolone, dexamethasone, etc.), charcoal or cream can be applied topically. The pus and secretions in the external ear canal can be cleaned with 3% hydrogen peroxide. 4. After the boil matures, the pus head can be picked up or drained by incision in time. 5.