Rashes - non-infective

Question 1

Nikolski sign

Answer 1

when excepting tangential pressure on apparently normal skin, particularly near vesicles, the epidermis or parts of it may be detached in certain bullies diseases
epidermolysis bullosa, TEN, SJS

Question 2

Miliaria

Answer 2

obstructions of eccrine duct resulting in rupture of the ducts and sweating into skin
miliaria crystalline - most common type
fragile 1-2mm clear, non-inflammatory vesicles without surrounding inflammation

miliaria rubra - intra-epidermal obstruction of the sweat duct with sweat leakage around the ducts
secondary local inflammatory response = erythema
papules and vesicles
later than MC
face neck trunk
prevent overheating = lesions resolve rapidly

Question 3

Epidermolysis Bullosa

Answer 3

lethal mechanobulbous disorder
neonatal vesicles, bullae and denuded skin, friction and trauma induced blistering are hallmark
genetic etiology
3 subtypes - simplex, junctional, dystrophic
certain types - lethal
clinically unable distinguish
Nikolski sign

Question 4

Erysipelas

Answer 4

superficial form of cellulitis involving dermis and upper subcutaneous tissue - usually due S pyogenes

Question 5

SSSS

Answer 5

Staphylococcal scalded skin syndrome
epidermolytic toxin mediated
cutaneous tenderness and superficial widespread blistering and desquamation

Question 6

erythema nodosum

Answer 6

tender red subcutaneous nodules on extensor surfaces of lower legs
peak age 10-14 years
associated TB, Streptococcus, Yersinia, infective endocarditis
panniculitis - inflammation of the subcutaneous fat
septal panniculitis without vasculitis

Question 7

Scabies

Answer 7

Class Arachnida
Night itching on hands, wrists, buttocks, feet, soles, neck, skin folds
Scratching excoriations due to intense itching
Various degrees of crusting and scaling
Lichenified skin or 2-4mm granulomatous nodules
hyperpigmentation from chronic irritation
infants - nodular reaction seen in intertriginous areas but may be generalised

tired and irritable
fever and lymph adenopathy - secondary infection
acute glomerulonephritis if infected group A streptococcus
scabies lesions on the hand of infant - erythema, nodules and crusting

complications
secondary bacterial infection - strep pyogenes or staph aureus
pyodermatous sequelae of scabies
chronic nodular scabies with pyoderma and crusting
secondary infection = crusted purulent sores - echtyma

Treatment
Lindane or Quellada lotion - gamma benzene hexachloride - below neck - application left on 8 hours and then washed off thoroughly
infants + young children - sulphur ointment 3x daily for 3 days
tetmosol soap
benzyl benzoate - 24 hours
permethrin - 70-80% ovoidal activity - rinse 10minutes §

Question 8

Ancylostoma braziliense

Answer 8

dog and cat hookworm
eggs passed faeces dog or cat
defecate in sandboxes, parks or beaches
penetrates intact skin - larvae - migrates pruritus, linear erythematous, raised serpiginous tracts
cutaneous larva migrant occurs in feet
larvae tunnels in epidermis because cannot penetrate basal layers

topical thiabendazole
oral albendazole
antibiotics for secondary

Question 9

Treatment Tinae corporis or capitis

Answer 9

Imidazole - corporis

Griseofulvin - capitis

Question 10

Malassezia yeast

Answer 10

ketoconazole shampoo or fluconazole

Question 11

Pediculosis Capitis

Answer 11

human head louse Pediculus captitis 
pruritus 
nits adhering hair 
prefer clean, healthy hosts 
found people good hygiene and grooming habits 

female larger 
males brown bands traversing abdomen 
children 3-11 years 
         head-to-head and body contact 
         sharing objects to which lice cling 
girls more common 
may prefer certain blood types 

treatment
mechanical removal lice and nits with nit comb, shampooing and blow drying
most head lice products kill adult lice but not nits - all topical should applied twice, 1 week apart
Shampoos
gamma benzene hexachloride - Gambex
permethrin - lyclear, nitagon - applied twice
resistance problem both