This document provides information on fever, hypothalamus function, skin lesions, rashes associated with various infections, and hemorrhagic conditions. It defines fever and normal body temperature. It describes the roles of the anterior and posterior hypothalamus in temperature regulation. It lists and defines common skin lesions like macules, papules, nodules, vesicles, and bullae. It then describes rashes associated with measles, rubella, fifth disease, herpesvirus 6, and Epstein-Barr virus. It concludes with descriptions of hemorrhagic conditions like viral hemorrhagic fever, thrombotic thrombocytopenic purpura, and acute meningococcemia.

1. Dr.Shreya K S
Post Graduate in General Medicine
Bangalore

2. Definition : Elevation in the body temperature that
exceeds the normal variation and occurs in conjunction
with an increase in the hypothalamic set point.
 NORMAL: 36.8 degree celsius +/- 0.4
 FEVER : A.M Temperature >37.2 degree celsius or a
P.M Temperature >37.7 degree celsius.
 HYPERPYREXIA: Temperature of >41.5 degree celsius

3. Hypothalamus performs a major role
Anterior or rostral hypothalamus:
 It is the Heat-loss region,stimulation produces
cutaneous vasodilatation, sweating.
 It recieves afferents from Ruffini’s end organs and from
the temperature of the blood.
 Destruction of which causes Neurogenic fever.
Posterior or caudal hypothalamus :
 It is concerned with Heat production
 Stimulation causes cutaneous vasoconstriction,
shivering and increase in the metabolic rate through
release of TSH.

4.  Afferents reach this region from the peripheral cold
receptors (Krause’s end bulb), temperature of the
blood and from blood borne pyrogenic substances.
 Lesion results in poikolothermia.

5. PAPULE:
raised solid lesions
<5mm in diameter
NODULE:
raised solid lesions
>5mm in diameter

6. MACULE:
Flat lesions
change in colour.
PLAQUE:
Flat lesions, change in
color
>5mm in diameter

7. .
VESICLE:
circumscribed,elevated
lesions containing
fluid.
BULLAE: fluid filled
lesion >5mm
PUSTULE : raised lesions
containing purulent
exudate.

8. PETECHIAE : nonpalpable
purpura ,<3mm in
diameter
ECCHYMOSIS: nonpalpable
purpura,>3mm in
diameter.

9. PALPABLE PURPURA:
raised lesion due to
inflammation of the
vessel wall with
subsequent hemorrhage.
ULCER: defect in the
continuity of the
epithelium extending
atleast into the upper
layer of the dermis.
ESCHAR: necrotic lesion
covered with a black
crust.

10. TYPES OF ERRUPTIONS:
1. CENTRALLY DISTRIBUTED
MACULOPAPULAR ERUPTIONS
2. PERIPHERAL ERUPTIONS
3. CONFLUENT DESQUAMATIVE ERYTHEMAS
4. VESICULOBULLOUS OR PUSTULAR
ERUPTIONS
5. NODULAR ERRUPTIONS
6. PURPURIC ERUPTIONS

12.  Paramyxovirus
Incubation period around 10 days
fever, malaise,cough,conjunctivitis
2 days
Koplik’s spots
2days
Maculopapular rash
 begins behind the ears,neck and hairline
 spares palms and soles
 rash lasts for 3 days

13. KOPLIK’S SPOT: Bluish white dots around 1 mm in diameter
surrounded by Erythema on buccal mucosa opposite lower mucosa.
Fade with onset of rash

14.  Togavirus
 Incubation period: 14 days.
 50% cases subclinical
 Rash follows resolution of fever
 Spreads from hairline downwards.
 Rash lasts for 3 days.
 Associated with Forschheimer
spots,adenopathy,arthritis.

16.  Human parvovirus B19
 Incubation period: 7- 10 days
 Bright red “slapped-cheek” appearance
 Lacy reticular rash.
 Children aged3-12 years
 Arthritis in adults

19.  Human Herpes virus 6
 peak incidence in 9-21 months of age
 Follows resolution of fever
 Spares face
 Resolves within 2 days
 HH6 persists after infection in peripheral blood
mononuclear cells, CNS, salivary glands and female
genital tract.

20.  Epstein-Barr virus
 Diffuse eruption
 Periorbital edema
 Urticaria
 Palatal petechiae

22. EPIDEMIC TYPHUS :
 Rickettsia prowazekii
 Appears in axilla, trunk on 5th day, spreads to
extremities.
 Spares face, palms and soles
 Exposure to body lice, relapse after 30-50 years.
 10-40% mortality if untreated
 Headache and myalgia

23. ENDEMIC TYPHUS:
 Rickettsia typhi
 Spares palms and soles
 Flea born infection
 Headache and myalgia
SCRUB TYPHUS :
 Orientia tsutsugamushi
 Eschar at the site of mite bite
 Regional adenopathy
 Mortality upto 30% if untreated.

25. MEDITERRANEAN SPOTTED FEVER:
(Boutonneuse fever)
 Rickettsia conorii
 Eschar at the site of bite
 Eruption on proximal extremity
 Spreads to trunk and face.
 Exposure to ticks
 Regional adenopathy

26.  Leptospira interrogans
 Exposure to contaminated water
 Associated with conjunctivitis,scleral hemorrhages.
 Fulminant form
 Ictero hemorrhagic fever(Weil’s disease)

27.  Borrelia burgdorferi
 Erythema Chronicum Migrans:Papule expanding to
erythematous annular lesion with central clearing
 Concentric rings,induration or vesicular centre can be
associated.
 CNS involvement,myocarditis , photophobia, arthritis.

28. TYPHOID FEVER:
 Salmonella typhi
 Transient blanchable erythematous macules and
papules, 2-4 mm,usually on the trunk ROSE SPOTS
 Diarrhea,hepatosplenomegaly.
DENGUE FEVER:
 Flavivirus
 In 50%of cases
 Begins on the trunk and spreads centrifugally
 Petechiae on extremities

30. ERYTHEMA MARGINATUM:
 In Rheumatic fever
 Proximal extremities
 Evolving and resolving within hours
 Erythematous papules and plaques

32. SLE:
 Maculo-papular
 Photosensitive
 Malar rash, discoid lesions
 Palpable purpura, oral erosions

33. ROCKY MOUNTAIN SPOTTED FEVER :
 Rickettsia rickettsii
 Rashes beginnning on wrists and ankles
 Spreads centripetally
 Blanchable macules to petechiae
ERYTHEMA MULTIFORME:
 Target lesions
 Associated with drug reactions,herpes simplex or
mycoplasma pneumoniae infection.

35. BACTERIAL ENDOCARDITIS:
 OSLER’S NODES :
tender pink nodules on fingers
or toes
 Petechiae on skin
 Splinter hemorrhages
 JANEWAY LESIONS:
painless erythematous or
hemorrhagic macules,on
palms and soles.

36. SCARLET FEVER
 Gp A Streptococcus
 Blanchable erythema begins on face spreading to
trunk and extremities, circumoral lesions
 Sandpaper texture to skin.
 Pastia’s line,strawberry tongue
 Edema of hands,feet
 Desquamation in second week

38. KAWASAKI DISEASE:
 Scarlentiform rash
 Erythema multiforme
 Strawberry
tongue,conjunctivitis
 Desquamation later in
disease
 Associated with coronary
artery vasculitis.

39. STAPHYLOCOCCAL SCALED SKIN SYNDROME:
 Diffuse tender erythema
 Bullae,desquamation
 Nikolsky sign positive

41. STEVEN-JOHNSON SYNDROME:
 Associated with Drugs,HIV infection,GVHD
 Diffuse erythema or target like lesion,progressing to
bullae.
 sloughing and necrosis of entire epidermis.
 Dehydration and sepsis results in most cases.

43. PRIMARY HERPES SIMPLEX:
 erythema,grouped vesicles.
 may ulcerate,painful lesion
VARIOLA:
 red macules evolving into
papules and vesicles.
 Appears on face then spreads
centrifugally

44. VARICELLA:
 Macules evolving into papules
then vesicles,pustules.
 Sometimes umbilicated on an
erythematous base.
 Lesions appear in crops

45. RICKETTSIAL POX:
 Eschar found at the site
 Generalized rash involving face, trunk, extremities.
 Develops vesicles.
ECTHYMA GANGRENOSUM:
 Indurated plaque evolving into hemorrhagic bulla or
pustule
 Eschar formation.
 Common inaxilla,groin,perianal regions.

47. ERYTHEMA NODOSUM:
 Septal panniculitis
 Large,tender, violaceous,nonulcerative
subcutanoeaous nodules
 Usually on the lower limbs.
Causes:
 drugs: penicillins,sulfa drugs,OCPs
 Infections: streptococcal, mycobacterial,fungal

48.  Tender red or blue edematous nodules
 Vesiculation like appearance
 Usually on the face

51. 1. VIRAL HEMORRHAGIC FEVER
2. THROMBOTIC THROMBOCYTOPENIC PURPURA
3. ACUTE MENINGOCOCCEMIA

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