Differential diagnosis of Fever with rashes.

1. APPROACH TO FEVER WITH
RASHES
BY: DR. S. HARIS
SEMINAR PRESENTATION
DEPARTMENT OF MEDICAL MICROBIOLOGY
ATBUTH

2. OUTLINE
• Introduction
• Common skin lesions
• Evaluation of patient including history, physical examination and
laboratory investigations
• Overview of common diseases presenting with fever and rashes
• Summary and conclusion

3. Introduction
• Clinicians are often faced with diseases that are presented with fever
and rashes
• Some of these patients might be in life threatening condition or need
isolation in order to decrease its potential transmission to others
• The differential diagnosis of acute fever and rash is quite extensive
and includes a variety of infectious and non-infectious causes
• An accurate characterization of the skin lesions and a thorough
history can help narrow the differential diagnosis for a specific patient

4. Systematic Approach
• Obtain thorough history
• Characterize rash
• Assess for life-threatening illness
• Consider differential diagnosis
• Obtain diagnostic studies
• Determine need for empiric antimicrobial therapy

5. Patient Evaluation
History
• A detailed history can be quite helpful in identifying the cause of fever and
a rash
• A history of recent travel, woodland or animal exposure, drug ingestion or
contact with ill persons should be noted.
• Details about the rash should include site of onset, rate and direction of
spread, presence or absence of pruritus, and temporal relationship of rash
and fever
• Immune status is important because many of the diseases that result in
fever and a rash present differently in immunocompromised patients

6. Patient Evaluation Cont…
Physical Examination
• A basic understanding of the various types of rashes is essential in making
an accurate assessment and determining the severity and acuteness of the
patient's illness.
• The physician should identify the primary lesion but also note the presence
of secondary lesions. Important features include the distribution,
configuration and arrangement of the lesions
• In addition to evaluating the patient's vital signs and general appearance,
the physician should look for the following: signs of toxicity, adenopathy,
oral, genital or conjunctival lesions, hepatosplenomegaly, evidence of
excoriations or tenderness, and signs of nuchal rigidity or neurologic
dysfunction

7. Primary Skin Lesions

8. Secondary Skin Lesions

9. Skin Lesions
Macules Papules
Patch

10. Skin Lesions
Nodule Vesicle Bulla

11. Skin Lesions
Wheal
Pustules
Petechiae
Purpura

12. Patient Evaluation Cont…
Laboratory Data
• Laboratory data are not usually available during the initial evaluation
• The complete blood count with differential, an erythrocyte
sedimentation rate, a chemistry panel,
• liver function tests, and blood and urine cultures may prove useful in
identifying organisms or disease processes
• Aspirates, scrapings and pustular fluid may be obtained for Gram
staining and culture.
• Biopsy samples should be obtained from nonhealing or persistent
purpuric lesions.

13. Life-threatening Infections Presenting with
Fever and Rash
Infection Skin lesions Historical clues Diagnosis Treatment Isolation
Meningococcemia petechiae asplenia
Communal living
blood culture
CSF culture
Skin biopsy
Penicillin
ceftriaxone
yes
RMSF petechiae tick exposure
Spring
South central / midAtlantic US
serologyskin biopsy doxycycline no
Ehrlichia maculopapular tick exposure
Spring/ summer
serology
PCR
doxycycline no
Capnocytophaga petechiae dog exposure
Asplenia
blood culture penicillin
3rd gen ceph
no
Gram negative
Bacilli
papule, eschar neutropenia blood culture anti-pseudomonal
beta lactam +/- AG
Carbapenem, Cipro
no
Toxic Shock Syndrome erythema tampon use blood culture
skin culture
nafcillin
cefazolin, vanco
no

14. Life-threatening Infections Presenting with
Fever and Rash CONT……
Necrotizing Fasciitis erythema
bullae
trauma/ DM
obesity
tissue culture
blood culture
surgery
ABX based on site
no
Typhoid fever maculopapular international travel blood culture
Stool culture
ceftriaxone
quinolone
no
Viral Hemorrhagic Fever petechiae international travel Serology supportive possible
Acute Endocarditis petechiae IVDU
valvular disease
blood culture nafcillin or Vanco no
RMSF = Rocky Mountain Spotted Fever, CSF = cerebral spinal
fluid, PCR = polymerase chain reaction, AG = aminoglycoside,
Cipro = ciprofloxacin, 3rd gen ceph = third generation
cephalosporin, FQ = flouroquinolone, Vanco = vancomycin,
DM = diabete mellitus, ABX = antibiotics

15. Diseases Presenting with Fever and Rash
Maculopapular Rashes
• Maculopapular eruptions are most frequently seen in viral
illnesses and immune-mediated syndromes
• It is helpful to consider centrally and peripherally distributed
eruptions separately because each type has its own differential
diagnosis

16. CENTRALLY DISTRIBUTED ERUPTIONS
• Centrally distributed maculopapular eruptions are more common
than peripheral eruptions
• These eruptions include rashes that begin centrally, first affecting the
head and neck, and then progress peripherally.
• Viral Exanthems. Viral etiologies of rashes include rubeola, rubella,
erythema infectiosum and roseola
• Lyme Disease and Erythema Migrans. The pathognomonic rash,
develops in about 80 percent of patients with Lyme disease, This
enlarging, erythematous macular rash begins as a macule or papule at
the site of inoculation

17. Erythema migrans on upper arm in Lyme disease.
Maculopapular rash of
erythema infectiosum (fifth
disease).

18. PERIPHERAL ERUPTIONS
• Erythema Multiforme. The most common peripheral eruptive
maculopapular rash,
• The rash, which can be recurrent, shows a predilection for palms,
soles, knees and elbows
• Although erythema multiforme has a number of known etiologies
• Etiologies of Erythema Multiforme include both infectious and
noninfectious causes; drugs, HSV, mycobacterium tuberculosis,
chlamydia species, salmonella typhi,

19. Erythema multiforme associated with sulfa drug administration.

20. Petechial Eruptions
• Petechial rashes warrant immediate evaluation to rule out severe,
life-threatening illness.
• Prompt, accurate diagnosis and early treatment can be life-saving in
patients with meningococcemia, rickettsial infections and bacteremia

21. Diffuse Erythema with Desquamation
• Scarlet fever provides the classic example of an erythematous rash
with subsequent desquamation.
• Toxic shock syndrome and scalded skin syndrome

22. Vesiculobullous-Pustular Eruptions
• VARICELLA-ZOSTER VIRUS INFECTIONS
• Monkeypox
• Staphylococcal bacteremia may present with a widespread pustular
eruption
• Gonococcemia may also produce a pustular rash, although other
lesion types, such as macules, petechiae and papules, are usually
present

23. Dermatomal distribution of rash in herpes zoster.

24. Nodular Eruptions
ERYTHEMA NODOSUM
• is an acute inflammatory and immunologic process involving the
panniculus adiposus
• A number of etiologies have been identified
• This condition is more common in women than in men.
• Etiologies can be both infectious and noninfectious
• Infectious include GAS, HepC, M.Tb,
• Noninfectious agents like sulfonamides, oral contraceptives, SLE,
ulcerative colitis, sarcoidosis

26. • THANK YOU FOR LISTENING

27. REFERENCES
• https://www.lecturio.com/concepts/primary-skin-lesions/
• http://antimicrobe.org/new/printout/e8printout/e8Approach.htm
• https://www.aafp.org/pubs/afp/issues/2000/0815/p804.html