Pruritis

Question 1

Localised pruritis

Answer 1

1. Causes:
   Eczema
   Scabies
   Dematitis herpatiformis
   Urticaria
2. Dry skin
   3.

Question 2

Generalised pruritis

Answer 2

Systemic disease
Pregnancy - esp in OCP use
Cholestasis
CKD
Hodgkins
Leukemia

Question 3

Scabies

Answer 3

1. Sarcoptes scabiei- female mite .. eggs.. hatch .. tiny mites .. itching
2. Very itchy, worse after hot shower
3. Maculopapular rash
4. Dxt: Microscopy of skin scrapings (Delta sign/Jet with contrail pattern), IgE test
5. Rx:
   ●Adults- might have to repeat after 1wk
   <2mo - Chrotamiton- 24hrs

> 2mo, 1st line:Permethrin 5% - overnight

2nd line: Benzyl benzoate 25% - 24hrs

3rd line: Ivermectin - repeat after 7days (does not kill eggs)

●<6months age
Sulphur 5%
Chrotamiton 10%
6. Itch increases after rx, resolves in 4wks

Wash bedsheets/linens in hot water
Treat all fam members

Question 4

Dermatitis herpatiformis (immunological)

Answer 4

1. Herpes simplex like vesicular rash - ulcer on presentation
2. On extensor surfaces - knee/elbow
3. A/w Coeliac disease - gluten sensitivity
4. Rx: Gluten free diet
   Dapsone for intense itchiness

Question 5

Lichen planus (immunological)

Answer 5

1. Raised violecious papules
2. Wrist, legs, oral mucosa - WICKHAM STRIAE (lace like)
3. 4Ps - papule, purple, polygonal, pruritic
4. Resolves by 6-9 months
   Itchy: Steroid cream mod-high potent

Question 6

Tinea cruris (fungal)
(6,7,8 similar)

Answer 6

1. Fungal JOCK itch (groin)
2. A/w Tinea pedis (foot)
3. Well defined border with scaling margins
4. Dxt: Skin scraping microscopy
5. Rx:
   Terbinafine 1% cream 1-2wks
   Severe itch - Hydrocortisone
   Tolnaftate dusting powder

Question 7

Candida intertrigo (fungal)
(6,7,8 similar)

Answer 7

1. Candida albicans
2. DM, long term antibiotic, immunocompromised
3. Red macerated rash @ skin folds
4. *Satellite lesion, white discharge , not well defined margins
5. Rx: Miconazole/cotrimazole cream 2wks

Question 8

Erythrasma (bacterial)
(6,7,8 similar)

Answer 8

1.Corynebacterium minutissimum
2.Reddish-brown scaly Rash @ skin fold, NO ITCH
3. CORAL PINK FLUORESCENCE IN WOODs LIGHT
4. Miconazole oint (even if bacterial infection)
Erythromycin oint
If necessary oral erythro/roxithromycin

Question 9

Rosacea

Answer 9

1. Unknown etio
2. F 30-50yrs
3. Forehead, cheek, nose, chin- FLUSHING AND BLUSHING, spared peri-oral area
4. A/w blepheritis, conjunctivitis
5. Rx:
   ●Avoid sun, heat, alcohol, spicy food, coffee
   ●Sun protection
   ●*NO STEROID - rebound vascular changes
   ●Mild - Metronidazole cream
   ●Severe - Doxy 8-10wks
   ●If no change … Minocycline oral
   ●If preg - erythromycin oral

Question 10

Tinea corporis (fungal)

Answer 10

1. Trychophyton rubrum, Microsporum canis
2. Cats, dogs, guinea pigs(face)
3. RINGWORM - red raised margins, central pale area
4. Rx:
   ●Terbinafine cream 1-2wks
   ●If not, clotrimazole/micona/ketokonazole
   ●No response,
   Oral Terbinafine 6wks

Question 11

Tinea capitis

Answer 11

1. Mycoplasma canis, Trichophyton tonsurans
2. Scaly lesion on skull - partial alopaecia
3. Dxt: Hair pulcking and scale for culture
4. Oral Terbinafine - Trichophyton tonsurans
   Oral Griseofulvine - Mycoplasma canis

Question 12

Pityriasis versicolor (tinea versicolor)

Answer 12

1. Malassezia
2. Variable colours -
   Brown pigm - on fair skin
   hypopigmented - on brown colour
3. Anywhere on body
4. Dxt: Skin scraping microscopy
5. Rx:
   Topical econazole
   Ketoconazole/selenium sulfide shampoo
   Persistent cases - Oral Fluconazole stat

Question 13

Pityriasis rosecea (viral)

Answer 13

1. Herpes virus 6,7
2. Children and young
3. Initial- HERALD RASH (similar to ringworm)
   ●After few wks- SALMON PINK ERUPTIONS
4. Following viral illness
5. Rx: Self limiting - 2-10wks
   itch - Steroid/calamine lotion

Question 14

Pityriasis alba

Answer 14

1. Penicillinase producing Staph aureus