Investigations r Third nerve palsy typically presents with pain order carvedilol 25mg with amex, A careful neurological examination should be carried diplopia and ptosis discount 6.25mg carvedilol overnight delivery. The important differential diagnosis is a spinal or cauda equina cause of the radiculopathy cheap 25 mg carvedilol mastercard. Complications Pyelonephritis, overgrowth of bowel bacteria causing di- Investigations arrhoea. Occasionally, it may be useful to exclude other Management causes, particularly in cranial nerve palsies when a space- Treatmentdependsonthesymptomsandcomplications. Postural hypotension is treatable with udrocortisone (a mineralocorticoid), but this may cause hypertension to be worse. Prognosis Symptomatic autonomic neuropathy is associated with Autonomic neuropathy areduced life expectancy. The hyperglycaemic and metabolic acidotic state which occursinTypeIdiabetesduetoexcessketoneproduction Pathophysiology as a result of insulin deciency. It is associated with bladder emptying, sexual function (erection and ejac- poor diabetic control. Life-threatening disturbances include reduced awareness of hypoglycaemia and cardiorespiratory ar- Pathophysiology rest. Infact,stressessuchasanintercur- r Postural hypotension, causing dizziness, faints and rent infection increase the secretion of glucagon and falls. Failure of ejaculation due to poses ketogenesis, but in conditions of insulin de- impaired sympathetic activity. Any un- cose concentrations rise, causing hyperosmolarity of derlying illness must be treated as appropriate. The renal threshold for glucose require a nasogastric tube for gastric decompression and reabsorption (10 mmol/L) is exceeded, and an os- emptying as there is a high risk of aspiration. Fluid and moticdiuresisoccurssothatwaterandelectrolytes,es- electrolytes: Patients can be as much as 10 L uid de- pecially sodium and potassium, are rapidly lost. Monitor uid balance causes a severe dehydration, hypovolaemia and this (urine output etc. A central venous compounds the problem by reducing renal perfusion, catheter may be placed to measure central venous pres- thereby reducing glucose clearance. Care must be taken not r Dehydration is exacerbated by vomiting, which is due to change the osmolality too rapidly, as this can lead to to central effects of ketosis. Replacement should be faster if Shock and acute renal failure, cerebral oedema may oc- patients are shocked and slower if there are signs of cur during rehydration, adult respiratory distress syn- cardiac failure, uid overload or cerebral oedema. Supplementa- tion is always needed, because potassium follows glu- Investigations cose into the cells. An arterial blood gas sample Insulin: Soluble insulin is administered intravenously by is also required to demonstrate and assess the severity of an infusion pump start with 10 units per hour and metabolic acidosis. Serum amylase greater than three- cutaneous or intramuscular insulin can reverse the ke- fold normal is suggestive of acute pancreatitis, which toacidosis. It therefore should not normally be used in the is rehydration and correction of electrolyte imbalances. It is the most common cause of death in diabetic patients under 20 Complications years old. Thromboembolic disease, such as stroke, mesenteric arterythrombosis,deepveinthrombosisandpulmonary embolism. Precipitating factors include infection, myocardial in- farction and stroke, or diabetogenic drugs such as glu- Management cocorticoids and thiazide diuretics. Patients require emergency uid resuscitation with nor- mal saline and potassium replacement (as for diabetic Pathophysiology ketoacidosis). Prophylactic low-dose heparin to prevent nesis, uncontrolled ketogenesis does not occur. Any underlying cause is insufcient insulin to prevent increased glucose pro- should be identied and treated. This compounds the hyperos- molarity caused by the hyperglycaemia, which increases Hypoglycaemia blood viscosity, predisposing to thromboembolic disor- Denition ders. If untreated, it leads to confusion and eventually Lowserumglucosecausedbyinsufcienthepaticglucose coma. Other tests causes include insulinomas (see page 222) and Addison s may be required to identify the underlying cause. Management Clinical features This is a medical emergency and requires immediate Patients become irritable, pale, weak and sweaty. Untreated the condition progresses to con- followed by a more complex carbohydrate to prevent fusion, seizures and coma. The diagnosis can be conrmed on bedside blood sugar r Further management depends on severity and the un- testing, a formal laboratory glucose sample should be derlying cause. Hypersplenism occurs when the spleen is func- Lymphadenopathy tionally overactive and can result from any cause of splenomegaly. The usual function of lymph nodes is to allow anti- gen recognition, proliferation and afnity maturation of mature lymphocytes. They usually become enlarged Bleeding tendency when active/reactive because of infection. Enlargement of lymph nodes can be localised or generalised (see Ta- Characterisation of a bleeding tendency requires multi- ble 12. Localised lymphadenopathy r Generalised haemostatic defects are suggested by Infection, e. It occurs in severe infections, tuber- blood vessels platelets and coagulation: culosis or malignant inltration of the bone marrow. This may result from marrow inltration or haemarthroses(bleedingintothejoints)andmuscle myelobrosis. It occurs with any cause of pancy- Investigations topenia, in association with rheumatoid arthritis (Felty s r Full blood count and blood lm to examine the num- syndrome). Alymphocytosis is seen in viral infections particularly r A full coagulation screen isperformed comprising a Epstein Barr virus and cytomegalovirus. An incision is made that is 1-cm long and Monocytes are the blood and bone marrow located pre- 1-mm deep. The time taken for bleeding to stop is cursors of tissue macrophages (including liver Kupffer measured. The bleeding time is prolonged in quanti- cells, pulmonary alveolar macrophages and Langerhan tative and qualitative platelet disorders. Factor assays can be used to measure the levels of any They are phagocytic and are involved in antigen process- components of the coagulation cascade. Amonocytosis may be seen in viral infections such as Investigations and procedures glandularfeverandinchronicbacterialinfectionssuchas endocarditis, tuberculosis and myelodysplasia. In cycli- Full blood count cal neutropenia the monocytes rise as the neutrophil The full blood count is the most commonly performed count falls. Neutrophils Aneutrophilia is seen in bacterial infections, tissue Basophils necrosis, inammation, myeloproliferative diseases and Basophils are thought to be the circulating equivalent corticosteroid therapy. A leukaemoid reaction is when of tissue mast cells, the granules contain proteoglycans, overproduction of white cells leads to the release of heparin, histamine. Coagulation screening tests True polycythaemia may be primary (see page 483) or secondary. Fibrinogen levels and Platelets brin degradation (D-dimers) products can also be Thrombocytopenia (reduced platelet count) may be due measured as a measure of intravascular clot break- to failure of bone marrow production or excess destruc- down, e. Peripheral platelet destruction may result from ofthromboplastinandthusmeasurestheextrinsicand immune mechanisms (see page 495), from excess coag- nal common pathway. It is also prolonged in liver nia and severe immunodeciency risking bacterial infec- disease and in patients taking warfarin. Blood is irradiated to prevent graft does not correct the time then the result is suggestive versus host disease. If heparin is suspected as the r Patients are maintained in a ltered air environment. Therearetwosamplingtech- cently peripheral blood stem cell transplants and cord niques available: blood. Coupled to this is a posi- the skin and advanced rotating clockwise and coun- tive phenomenon known as the graft versus leukaemia terclockwise until the marrow cavity is entered. Haemopoeitic progenitor r Gastrointestinal system: Abdominal pain dysphagia, cell transplantation odynophagia, weight loss, malabsorption and liver Haemopoetic progenitor cell transplantation is used disease.
Typically pyrosphosphate crystals are seen Xanthine Hypoxanthine within a phagolysosomal sac generic carvedilol 6.25mg on line, whereas urate crystals are Xanthine Oxidase not conned carvedilol 25 mg sale. Phagocytosis induces Uric Acid cytokine release leading to chemotaxis and further in- ammation cheap 6.25mg carvedilol otc. An acute inammatory arthritis resulting from urate An acuteepisodeofgoutmaybeprecipitatedbyasudden crystal deposition secondary to hyperuricaemia. Pathophysiology r Injointsanacutesynovitismayoccurwhenuratecrys- Age tals have been phagocytosed. Sex r If chronic, the crystals accumulate in the synovium 10M:1F and sites such as the ear cartilage forming lumps termed tophi. Theresultof urate damage is either tubulointerstitial disease (urate Aetiology nephropathy) or acute tubular necrosis. High levels of uric acid cause gout but not all individuals with hyperuricaemia will develop gout. Hyperuricaemia Clinical features is associated with increasing age, male sex and obesity, In 70 90% the initial attack of gout affects the big toe. These features ratesofuricacid production or decreased uric acid make it difcult to distinguish from a septic arthritis. Other joints affected include ankles, knees, ngers, el- r Increased uric acid production may be idiopathic or bowsandwrists. Chronicgoutisunusualbutmaycausea secondary to excessive intake or high turnover as seen chronic polyarthritis with destructive joint damage with in malignancy (especially with chemotherapy). Metabolic bone disorders Management Acute gout is managed with high dose nonsteroidal anti- inammatory drugs. Hyperuricaemia is treated only if Osteoporosis associated with recurrent gout attacks. Excess purines are excreted as xan- thine rather than uric acid, and the therapy is lifelong. Overall 30% of individuals will have a pathological frac- ture due to osteoporosis. It is thought that osteoporosis rophosphate production leads to local crystal formation. The risk of fractures increases with bone shed from the cartilage in which they have formed. Factors that can affect the re- modelling balance are as follows: r Sex: Females have a lower bone mass and a high rate of Clinical features bone loss in the decade following the menopause. This Chondrocalcinosis may be detected on X-ray in cartilage is largely oestrogen-dependent, early menopause and without joint disease. Acute joint inammation resem- ovariectomy without hormone replacement therapy bles gout most commonly affecting the knee and other predisposes. Examination of the joint uid will demonstrate posi- r Genetic factors implicated include the vitamin D re- tively birefringent crystals. Aetiology Pathophysiology Osteomalacia is usually due to a lack of vitamin D or its Although there is low bone mass it is normally min- activemetabolites,butitmaybecausedbyseverecalcium eralised. The structural integrity of the bone is During bone remodelling vitamin D deciency results in reduced, causing skeletal fragility. Clinical features Osteoporosis is not itself painful; however, the fractures that result are. Typical sites include the vertebrae, distal Clinical features radius(Colles fracture)andtheneckofthefemur. Other Onset is insidious with bone pain, backache and weak- symptomsofvertebralinvolvementarelossofheightand ness that may be present for years before the diagnosis is increasing kyphosis. Vertebral compression and pathological fractures may occur; a biochemical diagnosis may be made prior Investigations to onset of clinical disease. Investigations r X-rayinvestigationshowsfractures,abonescancanbe r X-ray investigation shows generalised bone rarefac- used to demonstrate recent fractures. Looser s zones bone density is difcult to assess as the appearance is may be seen in which there is a band of severe rarefac- dependent on the X-ray penetration. Maleswith A disorder of bone remodelling with accelerated rate of gonadal failure benet from androgens. Viral infections may also be involved in the aetiology, including canine dis- Genetic musculoskeletal temper virus and measles. Paget s disease may be due to disorders a latent infection in a genetically susceptible individual. Achondroplasia Pathophysiology Osteoclastic overactivity causes excessive bone resorp- Denition tion. There follows osteoblast activation in an attempt Achondroplasiaisaformofosteochondroplasiainwhich to repairthelesion. Clinical features Incidence Most patients are asymptomatic and the disease is dis- Commonest form of true dwarsm. On examina- Age tion the bone may be bent and thickened, most obvious Congenital, usually obvious by age 1. With widespread bone involvement there may be a bowing of the legs and con- siderable kyphosis. Disproportionate shortening of the long bones of the limbs with a normal trunk length. The head is large Investigations with a prominent forehead and a depressed bridge of Characteristically there is a very high serum alkaline the nose causing a saddle shaped nose. There is a large lumbar lordosis, which causes phate reecting the high bone turnover. A tri- ing periods of immobilisation in active disease the serum dent deformity of the hands may be present. Patients may develop neurological problems due to r Correction of deformities if necessary by surgical in- stenosis of the spinal canal; this may require surgical in- tervention. Denition Aheterogenous disorder with brittle bones and involve- ment of other collagen containing connective tissue. Denition Metastatic cancer is much more common than primary Aetiology bone cancer. Bluescleraresultfrom Two thirds of bone secondaries arise from adenocarci- a thinning of the sclera, which allows the colour of the nomas of the breast or prostate. Metastases usually appear in the Clinical features marrow cavity, damaging bone both directly through Features and classication are given in Table 8. Thetriadofotosclerosis, Patients may present with bone pain or a pathological blue sclera and brittle bones is termed van der Hoeve s fracture. Investigations TheX-raytypicallydemonstratesadestructivelyticbone Primary bone tumours lesion, although some metastases appear sclerotic (e. Vasculitis Management Symptomatic treatments include analgesia, local ra- Vasculitis is an inammatory inltration of the wall of diotherapy and chemotherapy, internal xation of any blood vessels with associated tissue damage. The underlying Investigations mechanisms of the disorders are not fully understood. There may ordersuchassystemiclupuserythematosus,rheumatoid be anaemia of chronic disease. Vasculitides may be considered according to the size of Management vessel affected (see Table 8. Moderate dose prednisolone is used, and the therapy is monitored and tailored to the response of inamma- Polymyalgia rheumatica tory markers. Generally treatment is required for 9 15 months,andprophylaxisagainstosteoporosisisessential Denition (see page 373). Aclinicalsyndromecharacterisedbypainandstiffnessin the muscles of the pelvic and shoulder girdle associated with the development of giant cell (temporal) arteritis. Temporal (giant cell) arteritis Prevalence Denition Common, affecting up to 1 in 150. A history of polymyalgia rheumatica is present in 50% of patients with giant cell arteritis, 15% of patients with polymyalgia rheumatica will develop giant cell arteritis. Patientspresentwithfever,severeheadache Clinical features and scalp tenderness over the inamed supercial tem- Gradual onset of pain, stiffness and perceived symmetri- poral or occipital arteries. Systemic arterial pulsation is progressively lost as the artery be- malaise, anorexia and weight loss may occur.
This is partially because fragrance is not a single ingredient but is instead a general name that includes a variety of individual fragrance ingredients purchase carvedilol 6.25 mg free shipping. It is important to read the actual ingredient list on products and avoid products that contain fragrance generic 12.5mg carvedilol with amex, perfume generic carvedilol 12.5mg with mastercard, or essential oils. Labels that claim that the product is unscented or fragrance free can be misleading. Unscented products may contain masking fragrance designed to eliminate odors, and fragrance-free products can sometimes include essential oils that the manufacturer may not consider as fragrance. There are two materials in the standard patch test tray that screen for allergy to fragrance. The fragrance blend is a mixture of eight common fragrance ingredients and can corroborate the diagnosis in about 80% of individuals allergic to fragrance. Balsam of Peru is a tree extract from El Salvador containing many constituents used commonly in fragrances that will cause a reaction in approximately 50% of fragrance-allergic patients. Formaldehyde-Releasing Preservatives Formaldehyde is still the most effective cosmetic preservative against gram-negative bacteria. Substances that release formaldehyde are therefore still commonly used in skin care and cosmetic products (16). Individuals allergic to one of these ingredients may cross-react to any of the other formaldehyde-releasing preservatives. Therefore, it is often good advice to avoid all of these substances if patch testing results to one of them are clearly positive. Parabens Parabens are the most common preservatives in skin care products and cosmetics. A person who has an allergic reaction to parabens may still be able to use paraben-containing products if they are only applied to undamaged skin. That is, almost all paraben allergic reactions occur on inflamed or cracked skin; this has been termed the paraben paradox (17). Foods containing various preservatives that are known to be topical contact allergens have been occasional causes of hand dermatitis in cooks and bakers. Euxyl K400 Euxyl K400 (phenoxylethanol and methyldibromoglutaronitrile) is an even more recent preservative system that will probably become a more common cause of contact allergy once it is used more frequently ( 19). Iodopropynylbutylcarbamate Iodopropynylbutylcarbamate is the newest preservative to be used in skin care and cosmetic products ( 20). Sorbic Acid Sorbic acid is another cosmetic preservative that occasionally causes allergic reactions ( 21). Thimerosol Thimerosol is primarily in liquid products for use in the eyes, nose, and ears ( 22). Glyceryl Thioglycolate Glyceryl thioglycolate is found in the acid permanent wave products used in salons ( 23). This is a common cause of contact allergy in hairdressers because latex gloves are not impermeable to it. The alkaline permanent waves predominate in retail stores and are also commonly used in salons. These products and many depilatories contain ammonium thioglycolate, which usually does not cross-react with glyceryl thioglycolate. Lanolin Lanolin is a moisturizing substance obtained from the sebaceous secretions of sheep ( 24). Therefore, lanolin-allergic individuals only need to avoid lanolin and lanolin alcohol, synonymous with the European terms wool wax and wool wax alcohol, and not other lanolin derivatives. Propylene Glycol Propylene glycol is a versatile ingredient that is both a solvent and a humectant ( 25). Toluene Sulfonamide/Formaldehyde Resin Toluene sulfonamide/formaldehyde resin is found in nail polish and is the most common cause of eyelid contact allergy ( 26). Nail polishes that use other resins in place of this ingredient can be used by persons who are allergic to this ingredient. Cocamidopropyl Betaine In recent years, there have been a number of reports of contact allergy to cocamidopropyl betaine ( 27). This ingredient is used in baby shampoos due to its gentleness and the fact that it does not sting when it gets onto the eyes. The sensitizer appears to be an impurity formed in the manufacture of the ingredient. The benzophenones, which include oxybenzone and dioxybenzone, are now the most common cause of contact allergy to sunscreens. Benzophenones are also found in nail products, hair products, textiles, and plastics. Colophony cross-reacts with abietic acid, abitol, and hydrobietic acid, which are also used in cosmetic products. Medications that Are Sensitizers A number of medications have been reported to cause allergic contact dermatitis. In the case of topical products, it is important to consider vehicle ingredients as possible contact allergens in addition to the active drug. Topical Steroids It is now appreciated that topical steroids are a fairly frequent cause of contact allergy ( 30,31 and 32). The two best screening ingredients for topical steroid allergy are believed to be tixocortol pivalate and budesonide. Cross reactions between structural groups can occur; Groups B and D often cross-react. Ethylenediamine cross-reacts with aminophylline (which contains 33% ethylenediamine by weight as a stabilizer), ethylenediamine and piperazine antihistamines such as hydroxyzine and cetirizine, ethylenediamine-related motion sickness medications and menstrual analgesics, and some antiparasitics. Neomycin and Bacitracin These ingredients often cause contact allergy because they are used on injured skin with damaged barrier function ( 33). This probably does not represent a true cross-reaction but rather reflects the fact that these two ingredients are often in the same products. Benzocaine Benzocaine cross-reacts with other benzoate ester anesthetics, such as procaine, tetracaine, and cocaine ( 22). Inorganics include mercury (thermometers), yellow oxide of mercury, ammoniated mercury (found in Unguentum Bossi and Mazon cream for psoriasis) and phenylmercuric acetate (a spermicidal agent and an occasional preservative in eye solutions). Also, systemic administration of mercurials can induce a severe systemic allergic reaction in a person topically sensitized to mercury. Also, moisture under jewelry from repeated hand washing is a common cause of irritant dermatitis to metals. The most common cause of skin discoloration to metals is due to the abrasive action of powders in cosmetic products on metal jewelry. Sweat will act on nickel to create a green/black tarnish that can induce an allergic contact dermatitis. Metal jewelry that contains a significant amount of nickel turns red when a drop of 1% dimethylglyoxime from a nickel test kit is applied to the surface. All alloys of steel, except most stainless steel, can cause nickel contact allergy. The nickel in stainless steel is so firmly bound that sweat will often not liberate it and it will not react with dimethylglyoxime. A significant amount of nickel is not only found in jewelry but also in bobby pins, safety pins, some non-U. Chromium Chromium causes both allergic and irritant reactions; however, allergic reactions are more common ( 35). When reactions to chrome products occur, the reaction is usually due to nickel in the product. Most allergic reactions to chromium are to chromates in tanned leather or cement, and these reactions tend to be chronic dermatitis. Chromates are the most common cause of contact allergy to leather and are used in soft tanned leather of the type commonly found on shoe uppers. Chromate reactions in cement workers are often severe, chronic, and may persist many years after exposure to cement has ended. Often, these individuals will only react to softer gold alloys or to gold objects subjected to perspiration and friction. Tattoos Several metals used in tattoos can cause allergic contact dermatitis: red tattoos contain mercury sulfide (red cinnabar); green tattoos contain chromium or chronic oxide; blue tattoos contain cobalt aluminate; yellow tattoos contain cadmium yellow (a possible cause of phototoxic reactions) ( 37). Type I latex allergy to gloves may present as a localized contact urticaria that can mimic an allergic contact dermatitis. Alternatively, latex protein can be inhaled on particles of powder from gloves and cause widespread urticaria and anaphylaxis. Therefore, the skin-prick test is still the gold standard for type I latex allergy testing.
Sneezing is the most characteristic symptom generic carvedilol 25mg line, and occasionally one may have paroxysms of 10 to 20 sneezes in rapid succession generic 25mg carvedilol free shipping. Sneezing episodes may arise without warning discount 6.25 mg carvedilol fast delivery, or they may be preceded by an uncomfortable itching or irritated feeling in the nose. Sneezing attacks result in tearing of the eyes because of activation of the nasal lacrimal reflex. The rhinorrhea is typically a thin discharge, which may be quite profuse and continuous. Because of the copious nature of the rhinorrhea, the skin covering the external nose and the upper lip may become irritated and tender. Purulent discharge is never seen in uncomplicated allergic rhinitis, and its presence usually indicates secondary infection. Early in the season, the nasal obstruction may be intermittent or more troublesome in the evening and at night, only to become almost continuous as the season progresses. If the nasal obstruction is severe, interference with aeration and drainage of the paranasal sinus or the eustachian tube may occur, resulting in complaints of headache or earache. The headache is of the so-called vacuum type, presumably caused by the development of negative pressure when air is absorbed from the obstructive sinus or middle ear. Patients also complain that their hearing is decreased and that sounds seem muffled. Patients also may notice a crackling sensation in the ears, especially when swallowing. Nasal congestion alone, particularly in children, occasionally may be the major or sole complaint. With continuous severe nasal congestion, the senses of smell and taste may be lost. Itching of the nose also may be a prominent feature, inducing frequent rubbing of the nose, particularly in children. Eye symptoms (pruritus erythema and lacrimation) often accompany the nasal symptoms. Patients with severe eye symptoms often complain of photophobia and sore, tired eyes. Because of irritating sensations in the throat and the posterior drainage of the nasal secretions, a hacking, nonproductive cough may be present. A constricted feeling in the chest, sometimes severe enough to cause the patient to complain of shortness of breath, may accompany the cough. This sensation of tightness in the chest is particularly bothersome to the patients with severe nighttime cough. Certain patients relate that nausea, abdominal discomfort, and poor appetite appear to occur with swallowing excess mucous. A characteristic feature of the symptom complex is the periodicity of its appearance. Symptoms usually recur each year for many years in relation to the duration of the pollinating season of the causative plant. The most sensitive patients exhibit symptoms early in the season, almost as soon as the pollen appears in the air. The intensity of the symptoms tends to follow the course of pollination, becoming more severe when the pollen concentration is highest and waning as the season comes to an end, when the amount of pollen in the air decreases. In some patients, symptoms disappear suddenly when the pollination season is over, whereas in others, symptoms may disappear gradually over a period of 2 or 3 weeks after the pollination season is completed. There may be an increased reactivity of the nasal mucosa after repeated exposure to the pollen ( 18). This local and nonspecific increased reactivity has been termed the priming effect. The nonspecificity of this effect was suggested by demonstration under experimental conditions that a patient may respond to an allergen not otherwise considered clinically significant if he or she had been exposed or primed to a clinically significant allergen. This effect may account for the presence of symptoms in some patients beyond the termination of the pollinating season because an allergen not important clinically by itself may induce symptoms in the primed nose. The symptoms persist because of the presence of molds in the air, which affect the primed mucous membrane. The presence of a secondary infection, or the effects of nonspecific irritants on inflamed nasal membranes, may also prolong rhinitis symptoms beyond a specific pollinating season. To a lesser degree, the symptoms of allergic rhinitis may exhibit periodicity within the season. These symptoms may diminish while it is raining because of the clearing of the pollen from the air. Dry, windy days aggravate the symptoms because a higher concentration of pollen may be distributed over larger areas. In addition to specific factors, nonspecific factors may also influence the degree of rhinitis symptoms. Overall, allergic rhinitis tends to increase in severity for 2 or 3 years until a stabilized condition is reached. Occasionally, patients spontaneously lose their hypersensitivity, for reasons that are not well understood. Some children will rub the nose in an upward and outward fashion, which has been termed the allergic salute. The eyes may exhibit excessive lacrimation, the sclera and conjunctiva may be reddened, and chemosis is often present. The skin above the nose may be reddened and irritated because of the continuous rubbing and blowing of the nose. Examination of the nasal cavity discloses a pale, wet, edematous mucosa, frequently bluish in color. Swollen turbinates may completely occlude the nasal passageway and severely affect the patient. The nose can initiate immune mechanisms, and the significance of mediator release from nasal mast cells and basophils in immediate-type allergic reaction is well established. On nasal reexposure to antigen, the mast cells degranulate, releasing a number of mediators of inflammation. Eosinophils release major basic protein, which may further disrupt the respiratory epithelium and promote further mast cell mediator release. There are strong correlations between the number of basophils and the level of histamine in the late reaction and between the number of eosinophils and the amount of eosinophil major basic protein ( 30), which suggest that these cells may participate in allergic inflammation by not only entering the nose but also degranulating. Other evidence for the participation of eosinophils in allergic inflammation is that eosinophils increase during the seasonal exposure ( 31,32), and the number of eosinophil progenitors in nasal scrapings increases after exposure to allergens and correlates with the severity of seasonal disease ( 33). Basophils may also participate in the late-phase allergic response because cell counts have confirmed increases of basophils from nasal lavage fluids. Although neutrophils enter the nose in larger numbers than eosinophils, their role in allergic inflammation is unknown. The heating and humidification of inspired air is an important function of the nasal mucosa. The highly vascularized mucosa of the turbinates in the septum provides an effective structure to heat and humidify air as it passes over them. The blood vessels are under the direction of the autonomic nervous system, which controls reflex adjustments for efficient performance of this function. The sympathetic nervous system provides for vascular constriction with a reduction of secretions. The parasympathetic nervous system enables vascular dilation and an increase in secretions. The protecting and cleansing role of the nasal mucosa is also an important function. Relatively large particles are filtered out of the inspired air by the hairs within the nostrils. The major portions of the nose, septum, and paranasal sinuses are lined by ciliated cells. The cilia beat at a frequency of 10 to 15 beats per minute, producing a streaming mucus blanket at an approximate rate of 2.
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