Rash

Question 1

Description of rash

Answer 1

1. Site - diffuse vs local: (Covered part and exposed part - photosensitive, butterfly rash)
2. Morphology ‘3S 5C’
   • size
   • shape: rings, mulitple form, irregular
   • surface: oily, dry, scaly, exudative, lichenification
   • colour
   • centre/ edge: active edge, target lesion
   • contour: flat, raised
   • consistency
   • compression –> Blanchable?

Question 2

Terms of rash

Answer 2

1. Macule: seen but not palpable
2. Papule: seen and felt : 5mm size
3. Vesicle: Blister 5mm size
   • may be pustular/ haemorrhagic/ clear fluid
4. Crust (dried exudate)
   • serous - honey colour
   • haemorrage - red
   • pustular - yellow/ green

5. Scale: abnormality in epidermal keratinization
•  Causes: 
•  •  Eczema
•  •  Contact dermatiits
•  •  Psoriasis
•  •  Infection - fungal
•  •  Icthyrosis
•  •  Pityriasis Rosea
•  •  Scalet fever

6. Weal: Raised skin because of oedema, may be with erythematous edge
7. Plaque: Circumscribed patched with flat surface
   • raised / sunkened, Ddx - Psoriasis, Morphoea
8. Burrow: Black, raised, linea = Scabies
9. Comedomes: Black keratin plug at pilo sebaceous opening = Acne
10. Fissure: crack at epidermis & dermis is exposed, painful
11. Lichenification: secondary to prolong friction/ chronic eczema - the dermis is thickened with prominent lines
12. Scar: Hyper / atropic, fixed to underlying tissue, skin around may show hyperpigmentation
13. Ulcer: Destruction of whole thickness of skin due to infection / inflammation / malignancy.
    • Edge - raised/ undermined, vertical/ sloping
    • Floor - dirty/ clean/ exudative
    • Surrounding - inflammatory / indurated
14. Petechiae / purpura / ecchymosis

Question 3

Facial rash Ddx

Answer 3

1. Photosensitivity
2. Butterfly rash: SLE, Dermatomyositis
3. Adenoma Sebaceum
4. Acne
5. Eczema
6. Seborrhoeic Dermatitis
7. Milia

N.B. distinguished by morphology and age of involvement

Question 4

Examination of Butterfly rash

Answer 4

1. Butterfly rash - rash involving both cheek and nasal bridge

2. Face - 
•  ?Cushingnoid
•  Pallor/ Heliotropic rash
•  Alopecia
•  Hirsutism
•  Oral ulcer

3. Ankle oedema
4. Systemic examinations
   • Hands- vasculitic rash, small joint inflammation
   • Proximal myopathy
   • Hepatosplenomegaly
   • CVS - pericarditis, murmur
   • Lung - pleurisy, pleural effusion
   • CNS - Hemiplegia, cranial nerve palsy, fundi for cytoid boidies
5. Measure BP
6. Urine for sugar and protein and RBC

Question 5

Rash in Lower Limb

Answer 5

1. History
•  Itchiness/ painful
•  trauma precipitated
•  joint symptoms
•  Abdominal Sx

2. Examination 
•  Petechiae, bruise - staging
•  Edematous
•  distribution / morphology
•  examination of joints
•  examine abdomen for hepatoslenomegaly and LNs

3. DDx 
•  HSP
•  NAI
•  Bleeding tendency
•  Erythema nodosum

Question 6

Maculopapular rash ddx

Answer 6

1. Infectious 
•  Bacterial - Scalet fever
•  Viral - Measles, rubella, Roseola infantum (5th disease)
2. Drugs
3. Erythema multiformi
4. Papula Urticaria
5. Guttae Psoriasis
6. Pityriasis rosea