Surface anesthesia also facilitates some endoscopic procedures such as bronchoscopy (visualization of the lower airways) or cystoscopy (visualization of the inner surface of the bladder)

Side effects
Localized side effects
Edema of tongue, pharynx and larynx may develop as a side effect of local anaesthesia. This could be caused by a variety of reasons including trauma during injection, infection, an allergic reaction, haematoma or injection of irritating solutions such as cold-sterilisation solutions. Usually there is tissue swelling at the point of injection. This is due to puncturing of the vein which allows the blood to flow into loose tissues in the surrounding area. Blanching of the tissues in the area where the local anaesthetic is deposited is also common. This gives the area a white appearance as the blood flow is prevented due to vasoconstriction of arteries in the area. The vasoconstriction stimulus gradually wears off and subsequently the tissue returns to normal in less than 2 hours.The side effects of inferior alveolar nerve block include feeling tense, clenching of the fists and moaning.The duration of soft tissue anaesthesia is longer than pulpal anaesthesia and is often associated with difficulty eating, drinking and speaking. Risks
The risk of temporary or permanent nerve damage varies between different locations and types of nerve blocks.There is risk of accidental damage to local blood vessels during injection of the local anaesthetic solution. This is referred to as Haematoma and could result in pain, trismus, swelling and/or discolouration of the region. The density of tissues surrounding the injured vessels is an important factor for Haematoma.
Additionally, the number of keratin-10 positive cells and HLA-DR expression was higher as compared to psoriasis. In ILVEN without associated psoriasis all T-cell subsets and cells expressing NK receptors were reduced as compared to psoriasis, except for CD45RA+ cells. In particular the density of CD8+, CD45RO+ and CD2+, CD94 and CD161 showed a marked difference between ILVEN without psoriasis and psoriasis itself. T cells relevant in the pathogenesis of psoriasis are markedly reduced in ILVEN without psoriasis as compared to psoriasis. Treatment
Reported treatments include topical agents, dermabrasion, cryotherapy, laser therapy, and surgical excision. These therapies have a high failure rate because of incomplete relief of symptoms, scarring, or recurrence. Though similar in appearance, ILVEN will not respond to therapies known to affect psoriasis. ILVEN can be very difficult to live with but can be treated. The most effective method is full-thickness excision of the lesion. CO2 Laser Surgery can resurface the skin to give a flat, smoother and more normal appearance, but does not remove the lesion. History
The condition later known as ILVEN was first described by Paul Gerson Unna in 1896. ILVEN appears very similar to psoriasis. However, it was not until 1971 that the disorder was described and clearly defined as a distinct entity by Altman and Mehregan in a case study of 25 patients. The Dupre and Christol described histopathological criteria in 1977. Epidemiology
ILVEN usually appears in infancy or early childhood. The condition is very rarely begun in adulthood. ILVEN occurs predominantly in females (female-male ratio, 4:1) with no racial predominance.