Skin

Question 1

What does Tinea look like?

Answer 1

Annular or arcuate scaly and itchy rash with a definite edge and central clearing as it expands. Tinea pedis occurs on the feet and tinea cruris on the groin

Question 2

What is the treatment of Tinea?

Answer 2

Imidazole topical preparation • Terbinafine (Lamisil) • Bifonazole (Sporanox) • Miconazole (Monistat) • Clotrimazole (Canesten) Lamisil PO required if nails involved (as shown by yellow discolouration). 2° nail infection with candida can occur.

Question 3

What is the pathogenesis of acne?

Answer 3

1. Increased sebum production
2. Outflow obstruction

Stasis of sebum leads to infection & subsequent immune reaction:

• ‘White-head’ (inflammatory) if comedo is closed
• ‘Black-head’ (non-inflammatory) if comedo is open
• Cystic acne occurs if the comedo becomes encircled

Question 4

What are the topial agents used to treat acne?

Answer 4

1. Benzyl peroxide (OTC)

• Used at night for 15mins, then 30mins, etc. until overnight
• Bleaching agent (beware of clothing)

1. Tertinoin / Retinoic acid

• Vitamin A derivative (not Abx)
• Excellent for blackheads (non-inflammatory acne)
• Cream applied to whole face, even when no acne
• More effective than benzyl but hphotosensitivity & irritation

1. Erythromycin (Eryacne) and Clindamycin (ClindaTech)

• Topical Abx
• Good for whiteheads (inflammatory)
• Used as cream on whole face

Question 5

What are the systemic Rx for acne?

Answer 5

1. ABx

• Tetracycline, Doxycycline, Minocycline, Erythromycin, Trimethoprim
• Minocycline used when no response to above two agents or poor SE profile

1. OCP

• Combined oral contraceptives that are likely to improve acne include those containing cyproterone, desogestrel, drospirenone or gestodene as the progestin.
• Cyproterone acetate in OCP formulations (2mg)
• Extra cytoproteroe acetate can be added
  1. Isotretinoin (Roaccutane)
• Vitamin A derivative
• Extremely high efficacy typically within 4-6months
• Last line therapy; also used for cystic cases
• SE’s: hLipids, photosensitivity, drying of mucous membranes, depression

Question 6

How is pityriasis rosea commonly described?

Answer 6

In young adults. Starts with one “herald patch” (a red, macular patch / plaque) and then spreads 1-20 days later in the T-shirt and shorts region.

Question 7

What is the prognosis of pityriasis rosea?

Answer 7

Pityriasis rosea clears up in about six to twelve weeks.

Question 8

What is the typical patient and where is the typical distribution of a rash from a fungal infection?

Answer 8

In diabetics. In creases (warm, moist areas) eg. under breasts, in groin.