Rash Diseases and Skin Infections

A Lecture Outline

© Hanuš Rozsypal
Scarlet fever | Kawasaki syndrome | Toxic shock syndrome | Measles | Rubella | Roseola infantum | Megalerythema infectiosum | Other infections with maculopapular rash | Allergic eruptions | Chicken pox | Herpes zoster | Herpes simplex | Other infections with vesicular rash | Meningococcal disease | Other infections with petechial rash | Erythema multiforme | Erythema migrans | Erythema nodosum | Condylomata acuminata

Dear colleagues

     I offer you a new promised web page about rash illnesses. I hope that it will bring you benefit. Write me if you have used it in studying. I welcome your comments and suggestions. By the way, I am going to attach views of full size photo.
     Thank you for your interest and I wish you a succesful exam of infectious diseases.



Rash (exanthem) = an acute cutaneous eruption in more parts of the body. It can arise due to the systemic effects of a microorganism on the skin.
Exanthematic infection = an infection where the rash is an obligatory, prominent, and fairly characteristic symptom.

According to the morphology the rashes are classified usually to five (or more) groups

Classification of maculopapular rash:

Scarlatiniform rash Rubelliform rash Morbilliform rash
Scarlatiniform rash
(<1 mm)
Rubelliform rash
(1-3 mm)
Morbilliform rash
(3-5 mm)

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Etiology: Streptococcus pyogenes - beta-haemolytic streptococci group A, less frequently C and G.
Incubation period: 2-7 days.
Symptoms and signs: Fever, tonsillitis, red strawberry tongue, generalized, fine, sandpapery rash.

Scarlet fever Strawberry tongue
Scarlet fever Strawberry tongue with remnats of white fur
Strawberry tongue Šrámek´s sign
Strawberry tongue Šrámek´s sign - pale papules surrounding fingernails

Rash ususally appears on the 2nd day of illness. First appearing is on the inguinal region. The rash consists of small pink-red maculopapules. Lesions tend to be accentuated in the skin folds, particularly in the region of the neck, axilla, antecubital fossae, and inguinal and popliteal creases. Pastia´s lines are linear arrays of petechiae in the skin folds.
Differential diagnosis: Infection due to Arcanobacterium haemolyticum, Kawasaki syndrome, toxic-shock syndrome.
Therapy: Prokain-benzylpenicillin (50 000 IU/kg.day IM 3 days), then bezathinpenicillin (0,6 MIU IM), alternatives: fenoxymethyl-penicillin (PO), macrolids, 1st gen. cephalosporins.

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Syndroma mucocutaneo-lymphonodulare

Definition: Febrile exanthematic disease usually with cardiac sequelae, that affects children younger than 5 years old.
Etiology: Unknown, probably reaction to toxins (superantigens) produced by staphylococci or streptococci.
Pathology: Systemic vasculitis, in particular coronary arteriitis, which may lead to myocardial infarction and sudden death.
Symptoms and signs: Fever, conjunctivitis, rash, injected pharynx with dry, cracked lips and red strawberry tongue, swelling of the palms and soles with subsequent peeling of the skin. The illness may last 2-12 weeks!
Lab tests: leucocytosis, extreme thrombocytosis, high CRP. Echocardiogram: coronary aneurysms.

Kawasaki syndrome Kawasaki syndrome
Kawasaki syndrome Kawasaki syndrome

Cracked red lips Swelling of the hands Peeling of the skin
Cracked red lips Swelling of the hands Peeling of the skin around the nails

Therapy: Polyvalent immunoglobulin, antiagregant agents (acetylosalicylic acid, dipyridamol).

Further reading: Rowley AH, Shulman ST. Kawasaki Syndrome. Clin Microbiol Rev 1998;11(3):405-414.
Full text on-line.

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Etiology: Staphylococci (Staphylococcus aureus) producing enterotoxin F, streptococci.
Pathogenesis: Some cases have been associated with the use of tampons during menstruation, other cases have followed staphylococcal infection at other sites.

Dermografism blanch

Dermografism blanch

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Morbilli (in Anglo-Saxon literature rubeola!)

Etiology: Measles virus (Morbillivirus)
Incubation period: 1-2 weeks (usually 9 days).
Symptoms and signs: Prodrome lasting several days, frequently consisting of fever (39-40°C), coryza, conjunctivitis, and cough. Koplik spots = white lesions on the buccal mucosa. Rash begins on the face 4 days after onset of symptoms. It spreads caudally over the next 3 days as the prodromal symptoms resolve. The rash lasts 4-6 days (it fades from the head downward). Desquamation may be present.

Koplik spots Measles Measles
Koplik spots Measles Measles

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Rubella, rubeola

Etiology: Rubella virus
Incubation period: 12-23 days (average 18 days).
Symptoms and signs: Mild prodrome, mild catarrhal symptoms, fever is rarely high. On the first, second or third day, the maculopapular rash appears. It begins on the face and neck and rapidly spreads to the trunk and extremities. It fades without desquamation in 3-5 days. Adenopathy commonly affects occipital nodes. Arthralgias are common in young women.

Rubella Rubella
Rubella Rubella

Complications: Congenital rubella.
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Exanthema subitum, sixth disease

Age: Infants.
Etiology: HHV-6, rarely HHV-7.
Incubation period: 1-2 weeks.
Symptoms and signs: Sudden onset, high fever that rapidly disappears on the 4th day. At this time, a rash that resembles rubella appears. The trunk is most affected.

Exanthema subitum

Exanthema subitum

Differential diagnosis: Allergy to antipyretics or antibiotics administered during prodromal phase.
Complications: Febrile cramps.

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Megalerythema infectiosum, fifth disease

Etiology: Parvovirus B19.
Incubation period: 1-2 weeks.
Symptoms and signs: Mild fever, sore throat, in many cases the prodrome is absent. Erythema on the face suggesting the marks of slapped cheeks, either concurrently or within a few days an annular and confluent erythematous rash emerges on the limbs and trunk. The rash usually resolves within a week, but can recur episodically for several weeks from exposure to heat (such as when bathing), cold, exercise, or stress.

Megalerythema infectiosum Megalerythema infectiosum Megalerythema infectiosum
Megalerythema infectiosum ("slapped cheeks" and rash on trunk) Megalerythema infectiosum ("slapped cheeks") Megalerythema infectiosum (rash on buttocks)

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Infectious mononucleosis: Ampicillin-induced rash.

Morbilliform rash Morbilliform rash
Morbilliform rash Morbilliform rash

Primary HIV infection: Morbilliform rash.

Primary HIV infection Primary HIV infection
Primary HIV infection - morbilliform rash Primary HIV infection - aphthous ulcers in the mouth

Typhoid fever: Rose spots (discrete pinkish macules or maculopapules) on the abdomen.

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Etiology: Allergic reactions to various drugs and other compounds

Scarlatiniform rash Morbilliform rash Morbilliform rash
Scarlatiniform rash Morbilliform rash Morbilliform rash

Morbilliform rash Erythematous exanthem Morbilliform rash
Morbilliform rash Erythematous exanthem Morbilliform rash

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Etiology: Varicella-zoster virus (VZV).
Incubation period: 10-23 days (average 17 days).
Symptoms and signs: Although there may be short prodrome of fever and malaise, rash is often the first evidence of illness. Laesions evolve in 5 stages: macules, papules, vesicles, pustulae, crusts. Typical laesion of the early stage is teardrop-shaped vesicle containing clear fluid, surrounded by reddened area (so called "glass pox"). Laesions appear in crops. Greatest concentration of the laesions occurs on the trunk, less on the face, extremities are generally less affected. Laesions in all stages may be found simultaneously. Most laesions are crusted by the 6th day. In many cases, the most irritating symptom is itching.

Chickenpox Chickenpox Secondary infection of chickenpox - impetigo
Chickenpox Chickenpox Secondary infection of chickenpox (varicella impetiginisata)

Complicatiions: Pneumonia, encephalitis, impetigo.

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Herpes zoster

Etiology: Varicella-zoster virus (VZV)
Pathogenesis: Reactivation of VZV lying dormant in cells of a dorsal root or geniculate ganglion.
Symptoms and signs: An attack of shingles begins with pain and hyperaesthesia. Within a few days a cluster of vesicles appears in an area of a sensory nerve root.

Herpes zoster faciei

Herpes zoster faciei

Complications: Facial paralysis (Ramsay-Hunt syndrome), encephalitis, keratitis, corneal ulcer, impetigo.
Sequelae: Postherpetic neuralgia.
Therapy: Aciclovir.

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Etiology: Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2)
Symptoms and signs: A cluster of vesicles on an erythematous base that progresses to mucocutaneous ulcerations. The common sites are lips, facial skin, nailbed etc.

Oral herpes:

Oral herpes

Oral herpes

Eczema herpetic(at)um (Kaposi´s varicelliform eruption): HSV infection of the skin affected with eczema. Illness may be febrile - and severe.

Eczema herpeticum

Eczema herpeticum (Kaposi´s varicelliform eruption)

Genital herpes: a) in men - lesions may be found usually on the prepuce or in the coronal sulcus. b) in women - lesions may be found on the vulva, vagina or cervix.

Genital herpes Genital herpes
Genital herpes in a man Genital herpes in a woman

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Hand-foot-and-mouth disease: Coxsackieviruses (types A16, A10, and A5).

Hand-foot-and-mouth disease Hand-foot-and-mouth disease
Hand-foot-and-mouth disease Hand-foot-and-mouth disease

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Etiology: Neisseria meningitidis (meningococcus)

Petechial eruption during meningococcaemia Petechial eruption during meningococcaemia Ecchymoses during meningococcal sepsis
Petechial eruption during meningococcaemia Petechial eruption during meningococcaemia Ecchymoses during meningococcal sepsis
(>3 mm)

Gangrene of feet

Gangrene of feet due to arterial thrombosis

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Causes of petechial eruption: Rickettsial infections, infection due to Streptococcus pneumoniae in an asplenic patient, enteroviral infections (Coxsackie A9, ECHO 9), EBV and CMV infection, atypical measles, viral haemorrhagic fevers (VHF), tropical malaria with DIC etc.

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Erythema exsudativum multiforme (Hebrae)

Etiology: Leading causative agents are HSV, EBV, Mycoplasma, Coxsackie B5, Adenovirus, but many cases are idiopathic or due to drug exposure.
Symptoms and signs: Laesions begin as macules and papules of dark red to brown colour, may develop into blisters and are symetrically distributed on the trunk and extremities. Predilection sites are knees, elbows, palms, and soles. Mucosal involvement is ususally present and it is painful. The severe form with mucosal involvement is called Stevens-Johnson´s syndrome.

Erythema multiforme Erythema multiforme Erythema multiforme
Laesions on elbows Laesions on hands Laesions on knees

Erythema multiforme Erythema multiforme
Inflammed and crusted lips Laesions on trunk

Therapy: Symptomatic, steroids.

Further reading: Léauté-Labrezea C, Lamireaub T, Chawkib D, Malevillea J, Taieba A. Diagnosis, classification, and management of erythema multiforme and Stevens-Johnson syndrome Arch Dis Child 2000;83:347-352.
Full text on-line.

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Erythema (chronicum) migrans

Definiton: EM is a cutaneous manifestation of 1st (early localized) stage of Lyme borreliosis.
Etiology: Borrelia burgdorferi, particularly B. afzelii.
Incubation period: 3-32 days (after the tick bite).
Symptoms and signs: Painless flat erythematous lesion with partial central clearing usually localized on the thigh, groin, axilla etc. The diameter is several centimeter. It may be present for days to several weeks.

Erythema migrans

Erythema migrans

Therapy: Doxycyclin, amoxycillin, macrolids.

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Erythema nodosum

Etiology: Association with tuberculosis, sarcoidosis, enteric infections (yersiniosis, salmonellosis etc.), herpetic and streptococcal infections.
Pathogenesis: Sensitisation to a number of agents.
Symptoms and signs: Tender nodular lesions on the shins.

Erythema nodosum

Erythema nodosum

Further reading: Somer T, Finegold SM. Vasculitides associated with infections, immunization, and antimicrobial drugs. Clin Infect Dis 1995;20(4):1010-1036.
Abstract on-line.

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Condylomata acuminata

Etiology: Human papillomaviruses (HPV).
Symptoms and signs: Papules with irregular, verrucous surface, located around both the external genitalia or the anus.

Genital warts Perianal warts
Gigantic genital warts Perianal warts

Therapy: Cryotherapy, podophyllin.


  • Džupová O. Exanthem of infectious origin. In: Hobstová J et al. Infectious Diseases. 1st ed. Karolinum, Prague 2003, pp.125-137
  • Emond RTD, Rowland HAK, Welsby PD. Color Atlas of Infectious Diseases. 3rd ed. Mosby-Wolfe, Times Mirror International Publishers Limited 1995

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The page was last updated 13-May-2004