Fever with Rash PDF

Fever with Rash Dr. N. Shirani Chandrasiri  List the common exanthematous fevers. Describe the aetiological agents causing different exanthematous fevers. Describe the pathogenesis (source, mode of transmission, portal of entry and virulence factors) of these infections. Identify the pa...

Fever with Rash Dr. N. Shirani Chandrasiri  List the common exanthematous fevers. Describe the aetiological agents causing different exanthematous fevers. Describe the pathogenesis (source, mode of transmission, portal of entry and virulence factors) of these infections. Identify the pathology underlying the common infectious diseases. Identify the laboratory diagnosis of these infections. Outline the management of these infections. Describe the prevention and control of these infections including any currently available vaccines. Exanthem “ a breaking out” Typically used to describe a rash that is widespread over the body, symmetric, and red with macules or papules, but without scales Exanthems are usually caused by viral or bacterial infections They can also be caused by drugs, toxins, or autoimmune diseases The rash may or may not be itchy Part of systemic illness with fever, malaise, and headache First disease: Measles, specifically rubeola, caused by the measles morbillivirus. Second disease: Scarlet fever, which occurs after an infection Streptococcus pyrogens (group A streptococcus). This can occur as a throat infection, strep throat. Third disease: Rubella or German measles, caused by the rubella virus. Fourth disease: "Dukes' disease" (probably a Coxsackievirus or echovirus infection) Fifth disease: Erythema infectiosum, caused by parvovirus B19 Sixth disease: Roseola infantum, caused by herpesviruses HHV-6 and HHV-7. Vesicles/blisters/ bullae Contain clear fluids May become pustules later Papules Raised spots Macules Not raised from skin Maculopapular rash Petichiae/Purpura/ Ecymosis Bleeding in to the skin Size Common viral exanthems Very infectious More common in childhood Can cause outbreaks/ epidemics High morbidity Adults get more severe disease  Viral exanthems include the human immunodeficiency virus (HIV) in its acute infection stage. Smallpox (now eradicated) produced an exanthem. Viral hepatitis and infectious mononucleosis caused by the Epstein- Barr virus may produce an exanthem Mpox and COVID 19 Bacteria Mostly due to toxins Staphylococcal toxic shock syndrome and Streptococcal toxic shock syndrome. Also scarlet fever Meningococci Mycoplasma pneumonia, Kawasaki disease, and rickettsial diseases can cause rashes Typhoid and typhus Chickenpox (Varicella) A rash that turns into itchy, fluid-filled blisters that eventually scab over. The chickenpox rash starts on the chest, back, and face before spreading to the rest of the body. Palms and soles spared Successive crops Incubation period 10-21d Fever with onset of rash Herpes virus - Double stranded DNA Chickenpox (Varicella) Clinical diagnosis PCR or antibodies can be done from Immunocompromised will have severe disease with haemorrhagic rash so they need prophylaxis with specific immunoglobulin (VZIG) Aciclovir is used in treatment as well as prophylaxis Vaccination Measles (Rubiola) Incubation period 10-21days Prodrome of runny nose, fever, cough Henry Koplik described the enanthem tiny spots in oral mucosa red with blue white centres Highly infectious Complications like acute otitis media, vial pneumonia, myocarditis, pericarditis, encephalitis (01/1000 cases) 7 to 10 d after the rash Less than 2y could get subacute sclerosing pan encephalitis (SSPE) German measles (Rubella) Symptoms are generally a low-grade fever, enlarged lymph nodes esp. posterior auricular and an itchy rash. Rubella results in a fine, pink rash that appears on the face, the trunk and then the arms and legs. Called 3 day measles rubella isn't as infectious or as severe as measles. Lacks post measles staining Togaviridae Rubi virus Positive sense RNA virus Erythema infectiosum Human parvo virus B19 IP 4 to 14d Preschool and school age children Prodrome minimum 1 to 3d or absent Slapped cheek with circumoral pallor Lacy reticular pattern or fading Rash can last 1 to 3 weeks Contagious up to the presence of rash Respiratory route Group A Streptococci Toxic shock syndrome Erysepelas Scarlet fever Erythema nodosum Erythema marginatum Virulence factors Erythrogenic toxins  Rash in scarlet fever Haemolysins  Streptolysin O (Oxygen labile - antigenic) Streptolysin S (Oxygen stable- haemolysis) DNAses  Hydrolyse nucleic acid C5a peptidase  Inactivates human C5a Pyrogenic exotoxins  SPE-A, SPE- B, SPE- C Streptokinase  Spread infection Hyaluronidase  Degrade hyaluronic acid M protein Helps in resisting phagocytosis by PMNL F protein Binds to host fibronectin and mediates internalization of bacteria into host cells Hyaluronic acid capsule  Antiphagocytic T protein R protein STSS The most common initial symptoms of streptococcal toxic shock syndrome (STSS) are fever and severe pain, which is abrupt in onset and usually precedes tenderness or physical findings Clinical findings of necrotising fasciitis (NF) are more prominent in the later stages and include pain and tenderness out of proportion to the appearance of the area, oedema, erythema, anaesthesia and bullae formation Laboratory diagnosis of Group A Cultures of blood and focal sites of infection should be taken in all cases of suspected iGAS, ideally before antibiotic therapy is commenced Throat, vaginal and anal swabs may indicate a portal of entry, although a positive result does not distinguish GAS infection from carriage Retrospective diagnosis using serological antibody tests should be considered, using acute and convalescent serums samples, in probable clinical cases of iGAS Meningococcal sepsis Neisseria meningitidis Gram negative diplococci Increasing incidence in Sri Lanka Common serotypes A, B, C, W135, Y Prison inmates Serotype B according to Dr Lilani Karunanayake’s publication Rapidly fatal Can isolate from vesicle aspirates , blood or CSF cultures Neisseria meningitidis Commonly colonises the nasopharynx Carriage prevalence increases through childhood ~ 5% in infants 24% in 19-year olds adulthood ~ 8% Incubation period 3-5 days with sudden onset of fever Cases do not usually have detectable carriage untill admission to hospital or shortly beforehand Rash is maculopapular, nonpluratic erythematous lesions Usually on extreamities sparing the body Peticheal rash in 75% Chemoprophylaxis Ciprofloxacin is the first line chemoprophylaxis Rifampicin is a suitable alternative Chemoprophylaxis is no longer recommended to eradicate carriage for any case treated with a cephalosporin Single dose of ciprofloxacin can be used for the prevention of a secondary case in pregnancy, because short duration treatment for other indications appears to be safe Cases do not need additional vaccination Treatment Penicillin Cefotaxime or Ceftriaxone Rickettsial infections Rocky mountain spotted fever R. rickettsii Tick Rickettsialpox R. akari mites wild rodents Scrub typhus Orientia tsutsugamushi Epidemic typhus R. prowosekii louse Murine endemic typhus R. typhi flea Typhus Scrub typhus is caused by Orientia tsutsugamushi. Scrub typhus is spread to people through bites of infected larval mites. Develop within 10 days of bite The most common symptoms of scrub typhus include fever, headache, body aches, and sometimes rash. Most cases of scrub typhus occur in rural areas of Southeast Asia, Indonesia, China, Japan, India, and northern Australia. Treated with doxycycline Symptoms and signs Fever and chills Headache Body aches and muscle pain A dark, scab-like region at the site of the bite (also known as eschar) Mental changes, ranging from confusion to coma Enlarged lymph nodes Rash How to investigate Rash may give a clinical diagnosis Viruses can be isolated but no longer done since cumbersome Serology paired samples of Ig M and Ig G Bacterial culture Blood cultures Throat swabs Vesicular fluid CSF Pleural fluid EDTA blood for PCR Treatment Symptomatic Hydration Antipyretics Anti histamines if pruritic Rest Nutrition Isolation till infectivity is over Chickenpox aciclovir Prevention Vaccination available for varicella, measles, rubella, meningococci Typhus none Due to long incubation period post exposure prophylaxis with vaccination possible for measles and chickenpox You need to know the EPI schedule