36 THE NOSE AND PARANASAL SINUSES factories, etc. are fruitful sources of infection from droplets spread by coughing, sneezing and even speaking. Overheated and overcrowded rooms lead to the easy spread of infection, and fresh ajr_s.hQuldJbe allowed to circulate widely. Resistance may be increased by a regularjmtake^tvitarnins, especially vitamin _£L Polyvalent va^cines-agaiast the common cold have proved successful in some patients if given in the late summer or early autumn, by reducing the frequency and severity of attacks, but this is by no means the general experience. FIBRINOUS RHINITIS This is characterized by the formation of a false membrane on the nasal mucosa, and is always associated with the presence of C. diphtheriae, but, in keeping with the reduced incidence of faucial diphtheria, the disease is now extremely rare in this country. SYMPTOMS. The symptoms are those of nasal obstruction and discharge which may be clear or mucopurulent, and is often combined with epistaxis. There is little general upset. The condition is infectious, and may persist for weeks if untreated. CLINICAL FEATURES. The mucous membrane of the inferior and middle conchae is covered with a greyish membrane which is rather difficult to remove, and leaves a bleeding surface on which the membrane re-forms. The membrane is indistinguishable from true diphtheria. TREATMENT. The patient should be isolated until the nose is clinically and bacteriologically clear, and a full course of penicillin should be given. CHRONIC HYPERTROPHIC RHINITIS This may result from repeated^c»te.attacks>_but it is predisposed to by certain occupations involving dust^atmospfaeres or exposure^ to cheinical irritants, ft may occur with a deflected, nasal septum or in patients -vi^^or^^saxos infection, and in those who are excessive in the us^joJ^c^hpXoxlPiaccp. SYMPTOMS. The main symptom is nasal_ pjbstrjicliQp, especially at night. If the obstruction is marked there may be impaired serjse_QLsinell,.and^lastfi. The nasal secretion may be either mucpid or viscid, and may be profuse in some patients. CLINICAL FEATURES. The nasal mucosa is congested, and areas_pf hyper- trophy are seen, particularly in the" anterior or posterior ends of the inferior concha. There may be a hypertrophic fringe running along the entire length of the inferior concha. The middle concha is less affected. The application of cocaine hydrochloride (10 per cent) on a pledget of cotton-wool will serve to distinguish true hypertrophy from vascular or allergic swellings which will shrink markedly. Posterior rhinoscopy shows the hypertrophy of the posterior ends of the inferior conchae as mulberry-like .swelliogs-^/tfte /, 3). TREATMENT. This varies with the degree of discomfort and the amount of hypertrophy. An early case mayjrespond to simple -decongestant sprays containing ephedrine hydrochloride, 1 per cent in normal saline, but the established hypertrophy may require surgical trirnming of the overgrown fringe or the mulberried posterior ends of the inferior concha. There is a danger in overzealous removal, which may produce a degree of atrophy.