Varicella (Acute Chickenpox, Zoster [Shingles]) ■ Essentials of Diagnosis • Acute varicella: fever, malaise with eruption of pruritic, centripetal, papular rash, vesicular and pustular before crusting; lesions in all stages at any given time; “drop on rose petal” is the first lesion • Incubation period 14–21 days • Bacterial infection, pneumonia, and encephalitis may complicate • Reactivation varicella (herpes zoster): dermatomal distribution, vesicular rash with pain often preceding eruption ■ Differential Diagnosis • Other viral infections • Drug allergy ■ Treatment • Supportive measures with topical lotions and antihistamines; antivirals (acyclovir, valacyclovir, famciclovir) for all adults with varicella • Immune globulin or antivirals for exposed susceptible immuno- suppressed or pregnant patients • Acyclovir early for immunocompromised or pregnant patients, severe disease (eg, pneumonitis, encephalitis), or ophthalmic division of trigeminal nerve involvement with zoster • Corticosteroids combined with antiviral agent with rapid taper may diminish postherpetic neuralgia in older patients with zoster ■ Pearl Epidemics are more frequent in winter and spring and in temperate cli- mates. Reference Weller TH: Varicella: historical perspective and clinical overview. J Infect Dis 1996;174(Suppl 3):S306. [PMID: 8896536] 202 Essentials of Diagnosis & Treatment 8 Mumps (Epidemic Parotitis) ■ Essentials of Diagnosis • Painful, swollen salivary glands , usually parotid; may be unilateral • Incubation period 12–24 days • Orchitis or oophoritis, meningoencephalitis, or pancreatitis may occur • Cerebrospinal fluid shows lymphocytic pleocytosis in meningo- encephalitis with hypoglycorrhachia • Diagnosis confirmed by isolation of virus in saliva or appearance of antibodies after second week ■ Differential Diagnosis • Parotitis or enlarged parotids due to other causes (eg, bacteria, sialolithiasis, cirrhosis, diabetes, starch ingestion, Sjögren’s syn- drome, sarcoidosis, tumor) • Aseptic meningitis, pancreatitis, or orchitis due to other causes ■ Treatment • Immunization is preventive • Supportive care with surveillance for complications ■ Pearl Mumps is a treatable cause of sterility, associated with high blood FSH and low testosterone levels. Reference McQuone SJ: Acute viral and bacterial infections of the salivary glands. Oto- laryngol Clin North Am 1999;32:793. [PMID: 10477787] Chapter 8 Infectious Diseases 203 8 Viral Encephalitis ■ Essentials of Diagnosis • Most common agents include enterovirus, Epstein-Barr virus, and viruses of herpes simplex, measles, rubella, rubeola, vari- cella, West Nile fever • Fever, malaise, stiff neck, nausea, altered mentation • Signs of upper motor neuron lesion: exaggerated deep tendon reflexes, absent superficial reflexes, spastic paralysis • Increased cerebrospinal fluid protein with lymphocytic pleocyto- sis, occasional hypoglycorrhachia • Isolation of virus from blood or cerebrospinal fluid; serology pos- itive in paired specimens 3–4 weeks apart • Brain imaging shows temporal lobe abnormalities in herpetic encephalitis ■ Differential Diagnosis • Other encephalitides (postvaccination, Reye’s syndrome, toxins) • Lymphocytic choriomeningitis • Primary or secondary neoplasm • Bacterial meningitis or brain abscess ■ Treatment • Vigorous supportive measures with attention to elevated central nervous system pressures • Mannitol in selected patients • Acyclovir for suspected herpes simplex encephalitis; other specific antiviral therapy is under study ■ Pearl In patients with suspected encephalitis, acyclovir is given until herpes is excluded. Reference Roos KL: Encephalitis. Neurol Clin 1999;17:813. [PMID: 10517930] 204 Essentials of Diagnosis & Treatment 8 Poliomyelitis ■ Essentials of Diagnosis • Enterovirus acquired via fecal-oral route; vast majority of symp- tomatic cases are not neurologic • Muscle weakness, malaise, headache, fever, nausea, abdominal pain, sore throat • Signs of lower motor neuron lesions: asymmetric, flaccid paral- ysis with decreased deep tendon reflexes, muscle atrophy; may include cranial nerve abnormalities (bulbar form) • Cerebrospinal fluid lymphocytic pleocytosis with slight elevation of protein • Virus recovered from throat washings or stool ■ Differential Diagnosis • Other aseptic meningitides • Postinfectious polyneuropathy (Guillain-Barré syndrome) • Amyotrophic lateral sclerosis • Myopathy ■ Treatment • Vaccination is preventive and has eliminated the disease in the United States • Supportive care with particular attention to respiratory function, skin care, and bowel and bladder function ■ Pearl Stiff neck after an enteric illness is a potential precursor of neurologic polio. Reference Melnick JL: Current status of poliovirus infections. Clin Microbiol Rev 1996;9:293. [PMID: 8809461] Chapter 8 Infectious Diseases 205 8 Lymphocytic Choriomeningitis ■ Essentials of Diagnosis • History of exposure to mice or hamsters •“Influenza-like” prodrome with fever, chills, headache, malaise, and cough followed by headache, photophobia, or neck pain • Kernig and Brudzinski signs positive • Cerebrospinal fluid with lymphocytic pleocytosis and slight in- crease in protein • Serology for arenavirus positive 2 weeks after onset of symp- toms; virus recovered from blood and cerebrospinal fluid • Illness usually lasts 1–2 weeks ■ Differential Diagnosis • Other aseptic meningitides • Bacterial or granulomatous meningitis ■ Treatment • Supportive care ■ Pearl One of the few causes of hypoglycorrhachia in a patient who appears to be well. Reference Barton LL et al: Lymphocytic choriomeningitis virus: reemerging central ner- vous system pathogen. Pediatrics 2000;105:E35. [PMID: 10699137] 206 Essentials of Diagnosis & Treatment 8 Dengue (Breakbone Fever, Dandy Fever) ■ Essentials of Diagnosis • A viral (togavirus, flavivirus) illness transmitted by the bite of the Aedes mosquito • Sudden onset of high fever, chills, severe myalgias, headache, sore throat • Biphasic fever curve with initial phase of 3–4 days, short remis- sion, and second phase of 1–2 days • Rash is biphasic—first evanescent, followed by maculopapular, scarlatiniform, morbilliform, or petechial changes during remis- sion or second phase of fever; first in the extremities and spreads to torso • Dengue hemorrhagic fever is a severe form in which gastro- intestinal hemorrhage is prominent and patients often present with shock ■ Differential Diagnosis • Malaria • Yellow fever • Influenza • Typhoid fever • Borreliosis • Other viral exanthems ■ Treatment • Supportive care • Vaccine has been developed but not commercially available ■ Pearl Dengue should always be considered in the febrile returned traveler with presumed influenza. Reference Rigau-Pérez JG et al: Dengue and dengue haemorrhagic fever. Lancet 1998;352:971. [PMID: 9752834] Chapter 8 Infectious Diseases 207 8 Colorado Tick Fever ■ Essentials of Diagnosis • A self-limited acute viral (coltivirus) infection transmitted by Dermacentor andersoni tick bites • Onset 3–6 days following bite • Abrupt onset of fever, chills, myalgia, headache, photophobia • Occasional faint rash • Second phase of fever after remission of 2–3 days common • Imbedded ticks, especially in children’s scalps, may cause paresis ■ Differential Diagnosis • Borrelliosis • Influenza • Adult Still’s disease • Other viral exanthems • Guillain-Barré syndrome (if paralysis present) ■ Treatment • Supportive for uncomplicated cases • With paresis, removal of tick results in prompt resolution of symptoms ■ Pearl A tick-borne disease of the western mountains not associated with paralysis. Reference Attoui H: Serologic and molecular diagnosis of Colorado tick fever viral infec- tions. Am J Trop Med Hyg 199859:763. [PMID: 9840594] 208 Essentials of Diagnosis & Treatment 8 Rabies ■ Essentials of Diagnosis • A rhabdovirus encephalitis transmitted by infected saliva • History of animal bite (bats, bears, skunks, foxes, raccoons; dogs and cats in developing countries) • Paresthesias, hydrophobia, rage alternating with calm • Convulsions, paralysis, thick tenacious saliva and muscle spasms ■ Differential Diagnosis • Tetanus • Encephalitis due to other causes ■ Treatment • Active immunization of household pets and persons at risk (eg, veterinarians) • Thorough, repeated washing of bite and scratch wounds • Postexposure immunization, both passive and active • Observation of healthy biting animals, examination of brains of sick or dead biting animals • Treatment is supportive only; disease is almost uniformly fatal ■ Pearl Bats are the most common vector for rabies in the United States, and even absent history of a bite, children exposed to bats indoors should be immunized. Reference Plotkin SA: Rabies. Clin Infect Dis 1998;59:763. [PMID: 10619725] Chapter 8 Infectious Diseases 209 8 Influenza ■ Essentials of Diagnosis • Caused by an orthomyxovirus transmitted via the respiratory route • Abrupt onset of fever, headache, chills, malaise, dry cough, coryza, and myalgias; constitutional signs out of proportion to catarrhal symptoms • Epidemic outbreaks in fall or winter, with short incubation period • Virus isolated from throat washings; serologic tests positive after second week of illness • Complications include bacterial sinusitis, otitis media, and pneu- monia • Myalgias occur early in course, rhabdomyolysis late ■ Differential Diagnosis • Other viral syndromes • Primary bacterial pneumonia • Meningitis • Dengue in returned travelers • Rhabdomyolysis of other cause ■ Treatment • Yearly active immunization of persons at high risk (eg, chronic respiratory disease, pregnant women, cardiac disease, health care workers, immunosuppressed); also for all over 50 • Chemoprophylaxis for epidemic influenza A effective with aman- tadine; zanamivir and oseltamivir effective against influenza A and B • Antivirals reduce duration of symptoms and infectivity if given within 48 hours • Avoid salicylates in children because of association with Reye’s syndrome ■ Pearl Complicating staphylococcal pneumonia is the most common cause of death in epidemics. Reference Stamboulian D: Influenza. Infect Dis Clin North Am 2000;14:141. [PMID: 10738677] 210 Essentials of Diagnosis & Treatment 8 Infectious Mononucleosis (Epstein-Barr Virus Infection) ■ Essentials of Diagnosis • An acute viral illness due to EBV, usually occurring up to age 35 but any age possible • Transmitted by saliva; incubation period is 5–15 days or longer • Fever, severe sore throat, striking malaise, lymphadenopathy • Maculopapular rash, splenomegaly common • Leukocytosis and lymphocytosis with atypical large lymphocytes by smear; positive heterophil agglutination test (Monospot) by fourth week of illness; false-positive rapid plasma reagin test (RPR) in 10% • Clinical picture much less typical in older patients • Complications include splenic rupture, hepatitis, myocarditis, thrombocytopenia, and encephalitis ■ Differential Diagnosis • Other causes of pharyngitis • Other causes of hepatitis • Toxoplasmosis • Rubella • Acute HIV, CMV, or rubella infections • Acute leukemia or lymphoma • Kawasaki syndrome • Hypersensitivity reaction due to carbamazepine ■ Treatment • Supportive care only; fever usually disappears in 10 days, lymph- adenopathy and splenomegaly in 4 weeks • Ampicillin apt to cause rash • Avoid vigorous abdominal activity or exercise ■ Pearl Mononucleosis is the most common cause of the otherwise rare anti-i hemolytic anemia. Reference Cohen JI: Epstein-Barr virus infection. N Engl J Med 2000;343:481. [PMID: 10944566] Chapter 8 Infectious Diseases 211 8 [...]... 1996;334:240 [PMID: 853 2002] 216 Essentials of Diagnosis & Treatment Pneumococcal Infections I Essentials of Diagnosis • Pneumonia characterized by initial chill, severe pleuritis, fever without diurnal variation; signs of consolidation and lobar infiltrate on x-ray ensue rapidly • Leukocytosis, hyperbilirubinemia • Gram-positive diplococci on Gram-stained smear of sputum; lancet-shaped only on stained... stain; they also thrive intracellularly— in contrast to pneumococci Reference Thestrup-Pedersen K: Bacteria and the skin: clinical practice and therapy update Br J Dermatol 1998;139(Suppl )53 :1 [PMID: 99904 05] 218 Essentials of Diagnosis & Treatment Staphylococcus aureus-Associated Toxic Shock Syndrome I Essentials of Diagnosis • Abrupt onset of fever, vomiting, diarrhea, sore throat, headache, myalgia... symptomatic and extremely toxic with the clinical picture noted, a relatively low-grade fever is virtually diagnostic of gas gangrene Reference Chapnick EK: Necrotizing soft-tissue infections Infect Dis Clinics North Am 1996;10:8 35. [PMID: 8 958 171] ) 220 Essentials of Diagnosis & Treatment Tetanus (Clostridium tetani) I Essentials of Diagnosis • History of nondebrided wound or contamination may or may not be... meningitis in which organisms are not seen on cerebrospinal fluid Gram stain (50 % of cases) Reference Salzman MB et al: Meningococcemia Infect Dis Clin North Am 1996; 10:709 [PMID: 8 958 1 65] 226 Essentials of Diagnosis & Treatment Legionnaire’s Disease I Essentials of Diagnosis • Caused by Legionella pneumophila and a common cause of community-acquired pneumonia in some areas • Seen in patients who are immunocompromised... suggest the diagnosis of cutaneous diphtheria Reference Galazka A: The changing epidemiology of diphtheria in the vaccine era J Infect Dis 2000;181(Suppl 1):S2 [PMID: 10 657 184] 224 Essentials of Diagnosis & Treatment Pertussis (Bordetella pertussis) I Essentials of Diagnosis • An acute infection of the respiratory tract spread by respiratory droplets • History of declined DTP vaccination • Two-week prodromal... outbreaks are laboratory-acquired where sheep are used in cardiovascular research Reference Maurin M: Q fever Clin Microbiol Rev 1999;12 :51 8 [PMID: 1 051 5901] 8 214 Essentials of Diagnosis & Treatment BACTERIAL INFECTIONS Streptococcal Pharyngitis I Essentials of Diagnosis • Abrupt onset of sore throat, fever, malaise, nausea, headache • Pharynx erythematous and edematous with exudate; cervical adenopathy... in one-third of untreated patients include intestinal hemorrhage or perforation, cholecystitis, nephritis, and meningitis I Pearl The development of tachycardia and leukocytosis in a patient with typhoid fever suggests ileal perforation until proved otherwise Reference Magill AJ: Fever in the returned traveler Infect Dis Clin North Am 1998;12:4 45 [PMID: 9 658 253 ] 228 Essentials of Diagnosis & Treatment. .. 1008 151 0] 236 Essentials of Diagnosis & Treatment Chancroid (Haemophilus ducreyi) I Essentials of Diagnosis • A sexually transmitted disease with an incubation period of 3 5 days • Painful, tender genital ulcer • Inguinal adenitis with erythema or fluctuance and multiple genital ulcers often develop • Balanitis, phimosis frequent complications • Women have no external signs of infection I Differential Diagnosis. .. of local shigella species; trimethoprim-sulfamethoxazole and ciprofloxacin are the usual drugs of choice I Pearl The first organism associated with reactive arthritis Reference Edwards BH: Salmonella and Shigella species Clin Lab Med 1999;19:469 [PMID: 1 054 9421] 230 Essentials of Diagnosis & Treatment Campylobacter Enteritis (Campylobacter jejuni) I Essentials of Diagnosis • Outbreaks associated with... elevated hematocrits from severe dehydration may lead to hyperviscosity of the circulation Reference Kaper JB et al: Cholera Clin Microbiol Rev 19 95; 8:48 [PMID: 77048 95] 8 232 Essentials of Diagnosis & Treatment Brucellosis (Brucella Species) I Essentials of Diagnosis • Invariable history of animal exposure (veterinarian, slaughterhouse) or ingestion of unpasteurized milk or cheese • Vectors are cattle, . 1999;17:813. [PMID: 1 051 7930] 204 Essentials of Diagnosis & Treatment 8 Poliomyelitis ■ Essentials of Diagnosis • Enterovirus acquired via fecal-oral route; vast majority of symp- tomatic cases. reemerging central ner- vous system pathogen. Pediatrics 2000;1 05: E 35. [PMID: 10699137] 206 Essentials of Diagnosis & Treatment 8 Dengue (Breakbone Fever, Dandy Fever) ■ Essentials of Diagnosis • A. Essentials of Diagnosis & Treatment 8 Infectious Mononucleosis (Epstein-Barr Virus Infection) ■ Essentials of Diagnosis • An acute viral illness due to EBV, usually occurring up to age 35 but any