Fever and a Rash
Professor Alison M Kesson
Infectious Diseases and
Microbiology
Approach to Diagnosis
• This is not easy !!!
• Rash may or may not be diagnostic
• Will need history, physical exam and
investigations
• HISTORY
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Prior infectious diseases
Immunisations
Travel
Prodromal illness
Contacts
Approach to Diagnosis
• PHYSICAL EXAM
– General state
– Temperature
– Conjuctiva
– Ears and throat
– Auscultation of chest
– Abdomen – liver and spleen
– Lymph nodes
Types of rashes
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Vesicles and Bullae
Purpura and ecchymoses
Macular
Papules
Urticaria
Erthema multifomae
Erythema nodosum
Vesicles and Bullae
Vescicles
• Result from a disturbance of cohesion of epidermal
cells or components of a basement membrane
zone associated with influx of fluid into or beneath
the site of disturbance.
• Vesicles < 1cm; bullae > 1cm
• Rapidly evolve into erosions, ulcers or crusts.
• Most are benign, others are rapidly progressive
and life threatening.
Vesicular rashes
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VZV
HSV
Enterovirus – hand foot and mouth disease
Impetigo
Contact dermatitis
Pemphigus
Pemphigoid
Incontinentia pigmenti
Epidermolysis bullosa
Burns
Drugs
Allergies
Vesicular rashes
• Solitary – lesions of streptococcal blistering
dactylitis
• Localised – staphylococcus bullous impetigo
• Grouped or clustered – herpes simples
virus infection
• Arranged linearly – shingles - Varicella
zoster virus
• Generalised – chickenpox - varicella.
Herpes simplex
Herpes simplex
www.flickr.com/photos/nojhan/472561609/
Chickenpox
www.doctorhagen.com/Chicken.htm
www.flickr.com/photos/nojhan/472561609/
Herpes zoster
Herpes zoster
Hand Foot and Mouth Disease
www.primehealthchannel.com/hand-foot-and-mout...
hardinmd.lib.uiowa.edu/.../handfootmouth.html
Herpangina
Bullae
• Staphylococcal scalded skin syndrome -SSSS
• Erythema multiforme (with HSV infection)
• The appearance of bullae caused by thermal
injury or hypersensitivity response to insect bite
are identical to that of bullous impetigo.
Haemorrhagic bullae
• May accompany septicaemia caused by gram
negative organisms – Ps. aeruginosa
(ecthyma grangrenosum)
• Neisseria meningitides
• necrotising soft tissue infections due to
Streptococcus pyogenes.
Erythematous Macules and
Papules
Maculopapular rashes
• Erythematous macules and papules are the most
common primary lesions seen during acute febrile
illness in children.
• Almost all viral and many bacterial exanthems that
occur in the first year of life are of this type, and many
conditions that ultimately manifest purpuric, vesicular,
urticarial or ulcerative cutaneous lesions first appear
as erythematous macules or papules.
• Most are brief, self-limiting, and uncomplicated.
Definitions
• Macules – circumscribes, flat, discoloured, not
palpable, erythematous or purpuric.
• Patch if > 1 cm
• Papules – circumscribed, solid, elevated, < 1cm.
• Plaques – elevated, flat top, > 1cm
History
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1. age
2. season
3. exposure to toxins or medications
4. exposure to an ill person
5. geographic location and travel
6. immunization history
7. history of previous illness
8. exposure to domestic or wild animals
9. pattern of evolution of the rash
10. associated symptoms and signs
Pathogenesis
1. infection of cells of epidermis, dermis or vascular
endothelium
2. host immunological reaction to infecting organism
3. circulating toxins
4. a combination of above.
Maculopapular rashes
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Measles
Rubella
Scarlet fever
Kawasaki disease
Erythema infectiosum-5th disease-Parvovirus B19
Roseola infantum-6th disease-HHV-6
Viral infection esp. enteroviruses - most common
Epstein Barr virus infection
www.primehealthchannel.com/hand-foot-and-mout...
Measles
CDC
CDC
Measles
CDC
CDC
Rubella
CDC
CDC
Parvovirus B19
CDC
CDC
barbraschroeder.com/muhanadoela/scarlet-fever...
barbraschroeder.com/muhanadoela/scarlet-fever...
www.thesun.co.uk/sol/homepage/woman/health/he...
Scarlet Fever
barbraschroeder.com/muhanadoela/scarlet-fever...
www.thesun.co.uk/sol/homepage/woman/health/he...
Kawasaki disease
ep.bmj.com/content/89/1/ep3.full
thejez256.wordpress.com/.../
Purpura
Purpura
• association with life threatening
infections from multiple causes.
• vascular injury or disorders of
haemostasis associated with platelet
depletion or dysfunction.
Purpura
• Purpura is sub divided into three forms
on the basis of size, depth and extent
of haemorrhage
– petechiae
– ecchymosis
– palpable purpura
Purpura
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Petechiae are purpuric macules < 2mm
extravasation of blood from capillaries, often appear over a short
time in crops or showers.
Isolated petechiae are a common finding in early blood stream
infection.
Lesions that blanch under pressure are not extravascular
blood.
Ecchymosis – all bruises are areas of bleeding into the skin
that differ from petechiae only by their larger size.
Purpura fulminans – Neisseria meningitides, or varicella zoster
virus,
large confluent purpuric patches, subsequently undergo
necrosis and scar formations.
Petechiae
• 60% have presumed or proven viral illness,
approximately
• 20% had invasive potential life threatening bacterial
disease, most commonly septicaemia with or without
meningitis
• 20% had a variety of other infectious and noninfectious conditions.
• Viruses generally cause vasculitis involving small
vessel, whereas bacteria tend to invade vessels of a
variety of sizes.
Ecchymosis
• Rare in infection
• Consider trauma and child abuse
Purpura
• Purpuric rash is caused by vasculitis (e.g, HenochSchonlein purpura) or defects in clotting factors.
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• Purpura fulminans and symmetrical peripheral
gangrene association with relatively benign infections
such as varicella or S. pyogenes.
• Congenital or acquired protein C or protein S or antithrombin 3 deficiency may cause a similar clinical
picture.
Purpura
• Palpable purpura – small vessel vasculitis
– meningococcus
– staphylococcus
– gonococcus
• Immune mediated vasculitis
– hepatitis B virus
– atypical measles
– chronic meningoccaemia
– bacterial endocarditis.
Blueberry muffin rash
• Blueberry muffin
rash - papable
• intradermal
haemopoietic tissue
• congenital rubella
Petechiae and purpuric
rashes
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Enteroviruses
Meningococcal infection
Henoch-Schonlein purpura
Idiopathic thrombocytopenic purpura
Leukaemia
www.australianprescriber.com/magazine/22/5/117/8/
Purpura - menigococcus
https://www.umm.edu/imagepages/2884.htm
www.australianprescriber.com/magazine/22/5/117/8/
Meningococcus
Urticaria
Urticaria
• Urticaria is a common problem.
• Sudden onset of circumscribed
erythematous, oedematous papules or
plaques often showing central clearance.
• A few millimetres to centimetres in bizarre
irregular shapes.
• Papular urticaria is a reaction to an arthropod
bite.
Urticaria
www.nlm.nih.gov/.../ency/imagepages/2482.htm
irasyafira.blogspot.com/2010/07/urticaria.html
Urticaria
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50%of urticaria associated with infections - Strep pyogenes is
most common.
Associated virus infections
– adenovirus,
– coxsachie viruses, A9, A16, B4, B5,
– echo virus 11,
– Epstein Barr virus,
– hepatitis viruses A, B, C,
– human immunodeficiency virus,
– measles virus,
– mumps
Urticaria
• Viral upper respiratory tract and gastrointestinal tract
infections are the primary infectious triggers of acute
urticaria in children.
• Urticaria can also occur in association with
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mycoplasma,
treponemal,
rickettsial
fungal
parasitic
• Kawasaki disease or in association with infestation or
bites of arthropods.
Erythema multiforme
Erythema multiforme
• Numerous manifestations in the skin from
erythematous macules, papules, vesicles, bullae or
urticarial plaques to patches of confluent erythema.
• Diagnosis is established by finding donut shaped
target lesions(iris or bullseye), with an erythematous
outer border and inner pale ring and an erythematous
centre.
Erythema multiforme
• HSV has been implicated in at least 60% of episodes,
and trigger nearly all episodes of recurrent disease.
• HSV antigens and DNA are present in skin lesions.
• Mycoplasma pneumoniae associated with Steven
Johnson syndrome, organism detected in skin
lesions.
• Stevens Johnson syndrome is characterised by
lesions that develop predominately on the
extremities, accompanied by involvement of 2 or
more mucosal surfaces.
Erythema multiforme
www.justanswer.com/medical/2iegk-11-year-old-...
www.wrongdiagnosis.com/.../4652.htm
l
Stevens Johnson syndrome
Papules, nodules and ulcers.
Papules and nodules
• A papule is a raised superficial lesion
that is less than 1cm in size.
• A nodule is a solid palpable lesion
greater than 1cm in size.
Molluscum Contagiosum
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Molluscum Contagiosum produces a papule in skin cause
largely by the presence of virions.
Pox virus replicates in the cytoplasm of host epithelial cells.
Acquired through direct contact with an infected person or from
fomites and is spread by auto inoculation.
Incubation periods is estimated to be 2-8 weeks or longer.
Discreet pearly skin coloured dome shaped smooth papule 15mm, central umbilication, a plug of cheesy material can be
expressed, occur anywhere on the body, predilection for face,
eyelids, neck, axillae, thighs.
Molluscum Contagiosum
mummahh.blogspot.com/2011/02/molluscum-contag...
Erythema nodosum
Erythema nodosum
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Sudden appearance of exquisitely tender erythematous 1-10 cm
nodules usually extensor surface of leg.
Lesions can develop on calves, thighs, trunk, upper limbs, head
and neck.
Rare in children , 2 years – adolescence.
Nodules enlarge over 2-3 days stabilise for 03 weeks then
resolve over 3-6 weeks leaving hyperpigmentaion – slow
resolution.
Erythema nodosum
• Associated with
– Group A streptococcus (Strep. pyogenes) infection
– Tuberculosis
– Yersinia enterocolitica
– Bartonella henselae (cat scratch disease)
– Drugs – sulphonamides
– Sarcoid
– Malignancy – leukaemia and lymphoma
– Behcet’s, Reiter’s, SLE, IBD.
Erythema nodosum
www.healthopedia.com/.../erythema-nodosum.html
http://www.empowher.com/condition/erythema-nodosum
Erythema nodosum
www.skinsight.com/adult/erythemaNodosum.htm
http://www.cmaj.ca/cgi/content/full/178/2/151/F218
• “Alison, when you know what is causing
the infection, you will know what is
causing the rash”.
• Prof James D. Cherry UCLA1990
Thank You
Questions