patient with rash
The clinical appearance of a rash, a thorough history, and some knowledge of pathology of common conditions are necessary to make an accurate dermatological diagnosis. Certain rashes follow a typical pattern anatomically and aid the diagnosis. Other rashes are important markers of systemic disease and must be recognized in acute medical presentations.

Skin problems are common, affecting up to one-third of the population during their lifetime. While most chronic skin diseases are not life threatening, many carry high morbidity related to discomfort, cosmetic embarrassment, social stigmatism and loss of work and earnings.

Causes of a patient with rash


  • Viral – Measles, rubella, Coxsackie, CMV, Herpes simplex, Varicella zoster, EBV, adenovirus, enterovirus, echovirus
  • Bacterial – Meningococcal, Streptococcal, Staphylococcal, Pseudomonas, Pneumococcal
  • Fungal – Dermatophytosis, Candidiasis
  • Rickettsial
  • Parasitic – Hookworm, Toxoplasma gondii
  • Protozoal – Post Kalaazar Dermal Leishmaniasis

Infestation: Scabies, Pediculosis
Eczema :

  • Contact dermatitis (Irritant, allergic)
  • Atopic dermatitis
  • Photodermatitis (Polymorphic light eruption, Phototoxicity or Photoallergy)
  • Seborrheic dermatitis
  • Nummular eczema

Drug eruptions: Exanthematous eruption, Fixed drug eruptions, Erythema multiforme, Urticaria, Photosensitivity

Nutritional causes: Kwashiorker (Flaky paint dermatosis), Deficiency of Vit. A (Phrynoderma – skin scaly and toad-like), Zinc (Acrodermatitis enteropathica), Niacin (Pellagra), Riboflavin (Cheilosis, seborrheic dermatitis), Hypopigmentation (Copper, biotin deficiency)

Endocrinal disorders: Addison’s disease, Diabetes mellitus


  • Connective tissue disorders: SLE, DLE, Dermatomyositis, Scleroderma, Mixed connective tissue disorders
  • Papulosquamous disorders: Psoriasis, lichen planus, pityriasis rosea
  • Bullous disorders: Pemphigus vulgaris, bullous pemphigoid, Chronic bullous disorders of childhood
  • Neurocutaneous syndromes: Neurofibromatosis, Tuberous sclerosis
  • Disorders of pigmentation: Vitiligo, Albinism
  • Disorders of keratinisation: Ichthyosis


Neonatal Rashes


  • Sebaceous hyperplasia
  • Erythema Toxicum
  • Milia
  • Salmon patch
  • Mongolian spots
  • Transient neonatal pustular melanosis

Non infectious potentially serious

  • Acrodermatitis enteropathica
  • Epidermolysis bullosa
  • Congenital ichthyosiform erythroderma
  • Neonatal pemphigus vulgaris
  • Urticaria pigmentosa

Infectious usually mild

  • Neonatal candidiasis
  • Impetigo neonatorum
  • Scabies

Infectious serious

  • Bacterial infections
    Chlamydia trachomatis, E.coli, H.influenzae, Klebsiella pneumoniae,
    Listeria, Pseudomonas, Staphylococcal, Streptococcal infection
  • Congenital candidiasis
  • Staphylococcal Scalded Skin Syndrome
  • Viral infection- CMV, Varicella, Herpes

History of a patient with rash

  • Age: Neonatal, Adolescent
  • When? Duration: Acute/chronic
  • Where it started?
Disease Site of first appearance
Measles Face – behind ears, near hairline
Rubella Face
Erythema infectiosum Cheeks
Scarlet fever Neck
Exanthem subitum Trunk
  • Evolution and progression: Extension, exacerbation, remission, recurrence Eg. In Chickenpox –pleomorphic, in crops, centripetal
  • Distribution: Flexural (Atopic dermatitis), Extensor (HSP), Areas exposed to sunlight or to chemicals
  • Type of lesion : Colour (Red, yellow, bluish), Fluid-filled, purulent
  • When it begins to disappear: Typhoid, Urticaria – few hours, Exanthem subitum – 24hrs, Measles – 4-5 days
  • Aggravating factors: (Photosensitivity, Urticaria, Eczema) eg. Food, Contact with any chemicals/plants/other substances, Sunlight, Heat/cold, sweating
Disease Rash on day
Varicella (Low grade fever, malaise, loss of appetite) 1
Scarlet fever 2
Exanthem subitum (High fever, mild pharyngitis, coryza, Fever decreases as rash appears) 3
Measles (Moderate fever, dry cough, coryza, excessive lacrimation, fever rises) 4
Typhus (high fever, chills, headache), Infectious mononucleosis (Fever, malaise, sore throat) 5
Dengue hemorrhagic fever 6
Typhoid (step-ladder pattern fever, toxic) 7
a patient with rash

Assosciated symptoms

  • Other rashes with fever: Infections, Drug fever, HSP, SLE, JRA, Kawasaki disease, Malignancy, IBD
  • Fever, headache, vomiting: Meningococcemia
  • Pruritus: Urticaria, Contact dermatitis, Atopic dermatitis, Insect bite, Scabies, Pediculosis, Fungal infection (tinea versicolor, tinea corporis), Lichen planus,
    Drugs (Cefaclor, aspirin, penicillin),
    Obstructive jaundice, Chronic renal failure
  • Pain: Herpes Zoster, Polyarteritis nodosa
  • Loss of sensation: Leprosy
  • Mucosal involvement: Koplik spots in Measles, Oral ulcers in SLE, Steven-Johnson syndrome
  • Joint involvement: HSP, SLE, Psoriasis (Dactylitis), Meningococcemia, Sjogren’s syndrome
  • Nail changes: Tinea, Candidial, Bacterial, Psoriasis
  • Bleeding from other sites: Bleeding disorders, DIC
  • Abdominal pain – HSP, SLE, IBD
  • Seizures, altered mental functions – Meningococcemia, SLE, HUS
  • Rash with ocular features:
    • –Measles
    • –conjunctivitis
    • –Kawasaki disease – non-exudative conjunctivitis
    • –Allergic conjunctivitis
    • –Herpes simplex, Herpes zoster, Adenoviral
    • –JRA, IBD, Behcet’s (uveitis)
    • –Chronic Bullous disease of childhood (conjunctivitis)
    • –Vit. A deficiency
  • Rash with CVS involvement: –Viral infections (myocarditis)
    –Bacterial endocarditis
    –Rheumatic fever
    –SLE (Pericarditis, myocarditis, endocarditis)
    –Kawasaki (Coronary artery aneurysm)
  • Rash with hepatic involvement: –Kwashiorkor, Sepsis, Toxins/Drugs, SLE
  • Hobbies, Occupation, H/o contact with allergens, irritants, h/o pets
  • H/o insect bite
  • H/o Drug intake
  • H/o immunosuppressive conditions
  • H/o Travel
  • H/o Trauma
  • Psychological problems: Cosmetic problem
  • Treatment history
  • Nutritional history
  • Past history of similar episodes, history of asthma, urticaria
  • Similar history in close contacts: Viral exanthem, scabies
  • Family history +ve: Atopic dermatitis, Psoriasis
  • Risk factors for HIV in parents
  • Social factors: Child abuse

General Examination

  • Vitals: BP- ↓in septic shock (DIC, meningococcemia), bleeding disorders, ↑in HUS. Temp – ↑ in infections, connective tissue disorders, malignancy, drug fever
  • Dyspneic in anaphylaxis (Laryngeal oedema, bronchospasm)
  • Pallor-HUS, SLE, infections, malignancy, bleeding disorders, aplastic anemia etc.
  • Icterus – liver disorders.
  • Edema– HUS, HSP
  • Lymphadenopathy
    • Generalised– malignancy, SLE, HIV.
    • U/L cervical- Kawasaki disease
    • Joint swelling/tenderness/ inflammation– JRA, SLE.
  • Bone pain- malignancies
  • Nutrition– signs of vitamin deficiencies
  • Laxity of joints and skin– Ehlers-Danlos syndrome.
  • Skeletal sys– (absent radii) TAR syndrome, Fanconi syndrome.

Physical Examination


# Hepatosplenomegaly-malignancy, SLE, ITP, HUS
# Signs of Intussusception / tenderness – HSP

CNS– meningococcemia ,SLE,HUS
ENT examination
Mucosal (oral, conjunctival, genital) lesions


  • Number, site, size
  • Type of lesion: Morphological Classification
  1. Maculopapular

  • Viral exanthem– measles, rubella, rubeola, erythrema infectiosum (parvo), roseola infantum, coxsackievirus, echovirus, adenovirus, CMV, Hep B infection
  • Bacterial- Strep pyogenes (Scarlet Fever), Staph aureus (TSS)
  • Other Infections- Sec. Syphilis, Lyme disease
  • Kawasaki disease
  • Drug Eruption- penicillin, tetracycline, sulfonamides, barbiturates, NSAIDS, salicylates
  • Erythema Multiforme due to herpes virus, EBV, Adenovirus, Chlamydia, Salmonella, Mycobacteria, Histoplasma
  • SLE
  1. Vesiculobullous:

  •  Viral –(HSV, Coxsackie, Enterovirus, Varicella & Herpes Zoster)
  •  Bacterial –Staphylococcal infection, Bullous Impetigo, Grp A streptococcal and pseudomonas infection
  •  Drug Rxn, Allergic Contact Dermatitis, Insect Bite
  •  Autoimmune blistering diseases of the skin
  • Intraepidermal bullous diseases: Pemphigus vulgaris, Pemphigus foliaceus
  • Sub epidermal bullous diseases: Bullous Pemphigoid, Cicatricial Pemphigoid, Epidermolysis Bullosa Acquisita, Chronic Bullous Disease of Childhood
  • Vesiculobullous diseases
  • –Nikolsky sign +ve→ Pemphigus, Epidermolysis bullosa
  • –-ve, flaccid blisters +nt →Bullous impetigo (subcorneal bulla), Contact dermatitis
  • –-ve, no flaccid blisters→ Bullous pemphigoid, CBDC, Contact dermatitis, Insect bite

Morphological Classification

1. Superficial

–Self-limiting → warts, molluscum
–Persistent, progressive → Basal cell carcinoma
2. Dermal
–Cystic→Epidermal inclusion cyst, milia, Dermoid cyst
–Solid → Yellow (Xanthoma), Brown (Pigmented nevus), Red (Pyogenic granuloma, Hemangioma), Annular → Granuloma annulare, Fibrotic → scar, keloid, Soft → Neurofibroma
3. Subcutaneous
–Indolent → Lipoma
–Rapid growth → Metastases (Neuroblastoma, lymphoma), Melanoma
4. Diffuse erythematous with peeling or desquamation
–Scarlet fever, Toxic shock syndrome, Kawasaki disease, SSSS, Stevens Johnson syndrome
5. Petechial/Purpuric/Hemorrhagic rashes:

Infections– Meningococcal, Pneumococcal, EBV, Echo virus, CMV, Rickettsial infections, Malaria and Listeria infection
Thrombocytopenia – ITP, TTP, HUS, DIC, Hypersplenism, Platelet dysfunction, Marrow failure-Leukemia, Marrow infiltrative disorders, Storage disorder, Myelodysplastic syndromes, Aplastic anemia
Disorders of blood vessel – HSP, Ehlers-Danlos syndrome
Trauma/child abuse

Examination of Rash

#Grouped (Warts, Herpes Zoster, Lichen planus)
#Linear – Exogenous agents (irritants, insect bite), Koebner phenomenon, Along blood vessels/lymphatics
#Koebner phenomenon: Appearance of rash at site of trauma (Psoriasis, Lichen planus, vitiligo)
#Diascopy: Blanching


Diagnosis – usually clinical

  • CBC, PBS– TC (↑ in infections, HSP, Kawasaki, May be ↓ in SLE), Eosinophilia in Scabies, Platelets (↓ ITP, DIC, SLE; May be ↑ in IBD, Kawasaki, HSP)
  • ESR – ↑ in infections, connective tissue disorders, Kawasaki, IBD
  • Coagulation profiles (Bleeding spots)
  • Gram staining (Bacterial, Candidial)
  • Culture for bacteria or fungi (Saboraud Dextrose agar)
  • Serology for infective organisms
  • Direct light microscopy( with KOH preparation)
    • Dermatophytes
    • Parasitic infestations
  • Tzanck smear
    • HSV infection
  • Bullous disorders (Acantholytic epidermal cells)
  • Immunofluorescence test
  • CBDC (Linear IgA at dermo-epidermal junction
    • HSP (IgA around vessel walls)
  • Woods light examination
    • Fungal disease
    • Pigment disorders
  • Tumours and subcutaneous malignant lesions
  • Measurement and monitoring of hemangiomas
  • Skin tests in allergy – Intracutaneous, Patch test
  • Skin biopsy (HSP, Malignancy)
  • Dermatosonography


Depends on severity:

  • Immediate care should be given to the patient presenting with shock
  • Oxygen
  • IV fluid boluses @20ml/kg (max-120ml/kg)
  • Inotropes
  • ICU care with continuous monitoring
  • Blood or PRP should be given if profuse bleeding/thrombocytopenia+
  • Broad spectrum i.v. antibiotics for sepsis, DIC
  • Antihistaminics, steroids- drug reactions, wasp bites etc.

Specific management of condition

Viral fever with rash– acyclovir in chickenpox, or symptomatic management of rash & fever.
Bacterial infections– systemic/ local antibiotics
Oral Cephalexin, Cloxacillin – generalized impetigo
Topical Mupirocin– Localised impetigo
Fungal infections– systemic/Local antifungal agents
Eczema – Avoid the irritant, allergen, Antihistaminic, local emollients, local steroids, Cutaneous hydration Scabies– 25% Benzyl benzoate or Permethrine 5% apply usually neck and below. Treat family members too, wash and dry all clothes
Drug reactions – Stop the causative agent
Photosensitivity – Use of sunscreens
Psoriasis – Steroids, Keratolytic agents (5-10% salicylic acid),Tar, UVB
Treatment of the systemic disease

Choice of medium used

  • Acute weeping lesions: Wet compresses followed by lotions or creams
  • Dry/scaly lesions: Ointments
  • Scalp/hairy areas: gels, solutions, shampoos
  • Powder: Intertriginous
  • Pastes: Zinc oxide paste in diaper area

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