Dermatology / Skin Flashcards
Risk factors for ACNE?
✔️ male gender (due to high levels of circulating androgens)
✔️ age (12-14 years for females, 14-18 years for males)
✔️ PCOS, metabolic syndrome / diabetes mellitus, obesity (high levels of circulating androgens)
✔️ oily skin type
✔️ family Hx of severe acne
✔️ diet high in food with high GI
✔️ physical inactivity
✔️ high humidity environment
✔️ drugs / medications (e.g. phenytoin, corticosteroids, quinine, some COCPs)
Pathophysiology of ACNE?
There are four main steps in the pathophysiology of acne:
- increased production of sebum from sebaceous glands (due to higher levels of circulating androgens)
- blockage of gland due to hyperkeratinisation
- secondary bacterial infection (usually S. aureus)
- inflammation due to infection
Outline the key features of ACNE.
✔️ open (whiteheads) and closed (blackheads) comedones)
✔️ papules and pustules
✔️ cysts and pseudocysts
✔️ scarring
✔️ adverse psychological and psychosocial effects
How is acne classified in terms of severity?
MILD: < 30 lesions
MODERATE: 30 - 125 lesions
SEVERE: > 125 lesions
Outline key lifestyle modifications in the management of ACNE.
✔️ avoid picking or scratching of the face
✔️ avoid excessive washing of the face
✔️ avoid use of oily sunscreens, creams, makeup etc.
✔️ diet focusing on low GI foods
✔️ avoid excessive sun exposure
✔️ regularly wash pillows and bed linen
It is also important to reassure the patient that most cases of acne resolve towards the end of puberty.
Key principles of management of MILD ACNE?
Keratinolytic agents –> helps to minimise keratinisation and breakdown excessive skin; prevents clogging of sebaceous glands
✔️ salicylic acid cream / aqueous solutions (5 to 10%)
✔️ benzoyl peroxide 2.5, 5 or 10%
✔️ retinoic acid cream
✔️ sulfur compounds
Topical antibiotics (e.g. doxycycline)
Oral contraceptive pill –> helps to regulate androgen production and circulation; may reduce sebum production by sebaceous glands
Key principles of management of MODERATE ACNE?
✔️ Keratinolytic agents (e.g. salicylic acid, benzyl peroxide)
✔️ Oral contraceptive pill, spironolactone (anti-androgen therapy)
✔️ Topical antibiotics (e.g. clindamycin, erythromycin)
✔️ Oral antibiotics (e.g. doxycycline 50 - 100 mg)
Key principles of management of SEVERE ACNE?
✔️ Specialist referral
✔️ Oral isotrenitoin
✔️ Higher dose oral antibiotics (e.g. oral doxycycline 300mg)
Outline the mechanism of action for ISOTRETINOIN.
Isotretinoin is a Vitamin A derivative. It is extremely useful in the management of moderate / severe acne, either as a topical or an oral agent.
Isotretinoin has numerous actions that influence the underlying cause of acne, including: ✔️ reduces sebum production ✔️ shrinkage of the sebaceous glands ✔️ reduced keratinisation ✔️ anti-microbial effects ✔️ anti-inflammatory effects
Outline indications for ISOTRETINOIN.
Indications include:
✔️ severe acne (nodulo-cystic form)
✔️ acne resistant to previous treatments (e.g. OCP, antibiotics, antikeratinolytic agents)
✔️ patients with significant scarring from acne
✔️ moderate acne that has a significant psychological / psychosocial impact on the individual
Outline principles of management in regard to ISOTRETINOIN use.
Initial Dose: 05 to 1.0 mg / kg / day (in two divided doses)
Maintenance Dose: 0.5 to 2.0 mg / kg / day (in two divided doses)
Total Duration: 16 to 20 weeks
Isotretinoin is teratogenic. Therefore, it should not be started in any woman who is pregnant or considering becoming pregnant in the near future. All females of child-bearing age should be placed on TWO forms of contraceptive (e.g. OCP + IUD).
What are some side effects of ISOTRETINOIN?
✔️ dry, chaffed or cracked lips ✔️ dry eyes ✔️dry skin on face and hands ✔️ nose crusting and nose bleeds ✔️ headache ✔️ thinning and loss of hair ✔️ propensity to sunburn ✔️ teratogenic to fetus
Risk factors for BCC?
✔️ male gender
✔️ > 35 years of age
✔️ previous BCC or other form of skin cancer
✔️ fair skin, blue eyes, blonde or red hair
✔️ occupational exposure / excessive exposure throughout lifetime
✔️ radiation exposure
✔️ damage to dermal layer of skin (e.g. thermal burn)
Key features of BCC?
There are two key features uniform to ALL types of BCC:
- pearly edges / border
- telangiectasia
Other features include: ✔️ slow-growing ✔️ nodular or flat (macule / plaque) ✔️ variable in size ✔️ spontaneous bleeding or ulceration
Outline some important subtypes of BCC and their key / differentiating features.
- nodular BCC –> most common; small nodule on sun-exposed areas; variable colour and size; pearly edges; telangiectasia; central depression / ulceration
- superficial spreading BCC –> macule / plaque; slowly evolving; slight scale
- morphoeic BCC –> usually found in mid-facial sites; waxy, scar-like plaque; wide and deep sub-clinical extension
- baso-squamous carcinoma –> mixed BCC / SCC; high rate of recurrence; infiltrative growth pattern
Outline the appropriate management for BCC.
The most appropriate management for BCC is EXCISIONAL BIOPSY, with margins of 3 to 4 mm.
Depending on histological report, it may be necessary to undergo further excision / surgery if there is remaining tumour.
Other forms of management include:
✔️ Moh’s Micrographic Procedure –> gradual, controlled excision of the lesion with evaluation of the tissue layer by layer to ensure complete removal
✔️ Cryotherapy –> suitable for superficial lesions with freezing by liquid nitrogen
✔️ Photodynamic therapy
✔️ Imiquimoid cream
✔️ 5 FU cream
✔️ radiotherapy
Risk factors for SCC?
✔️ male gender
✔️ > 45 years of age
✔️ previous SCC or other form of skin cancer
✔️ actinic keratosis (pre-malignant condition)
✔️ fair skin, blue eyes, blonde or red hair
✔️ occupational exposure / excessive exposure throughout lifetime
✔️ radiation exposure
✔️ damage to dermal layer of skin (e.g. thermal burn)
✔️ immunotherapy
Outline key features of SCC?
✔️ scaly / warty lesion ✔️ +/- crusting ✔️ grow over weeks to months ✔️ bleeding on touch ✔️ tender and painful ✔️ located on sun-exposed areas ✔️ variable in size
Outline key features that suggest an SCC is a HIGH RISK lesion.
✔️ >2 cm in size
✔️ located on vermillion of lip, ear, face or genitals
✔️ immunocompromised or elderly patient
✔️ histology shows thickness > 2cm OR histologically undifferentiated lesion
Outline the appropriate management for SCC.
The standard for treatment of SCC is EXCISIONAL BIOPSY maintaining margins of 5 to 10 mm. A flap or skin graft may be required to fix the defect.
Other forms of therapy include: ✔️ Moh's micrographic procedure ✔️ intensive cryotherapy ✔️ shave, curettage and electrocautery ✔️ radiotherapy
What is the ABCEDFG criteria for MELANOMA?
A - asymmetrical B - border (poorly defined) C - colour D - diameter (>6mm) E - evolving / elevated F - firm to touch G - growing
NB. The “ABCDE” component is relevant to superficial lesions. The “EFG” component is relevant to nodular lesions.
Risk factors for MELANOMA?
✔️ male gender ✔️ age > 35 years ✔️ family Hx ✔️ occupational exposure to UV radiation ✔️ excessive time in the sun / poor protection ✔️ previous BCC or SCC ✔️ multiple (>5) atypical naevi ✔️ fair skin, blonde hair, blue eyes ✔️ Parkinson's Disease
What are the two growth phases of melanoma?
- horizontal growth phase
2. vertical growth phase
Identify some important sub-types of melanoma and key features of each.
SUPERFICIAL SPREADING MELANOMA
✔️ characterised by horizontal growth phase
✔️ typically develops from a pre-existing lesion
✔️ presents as a flat, slow-growing lesion; confined to the epidermis
✔️ irregular border; asymmetrical; multiple colours; evolving etc
NODULAT MELANOMA
✔️ characterised by a vertical growth phase
✔️ typically presents without a pre-exising lesion
✔️ presents as a dome-shaped nodule
✔️ may have smooth or warty surface; bleeds on touch; ulceration is present
✔️ itchy or abnormal sensation
LENTIGINOUS MELANOMA
✔️ characterised by horizontal growth phase
✔️ always develops from a pre-exisining lesion (e.g. mole, freckle)
✔️ late-onset melanom; more common in men than women
✔️ ABCDE features are consistent with a melanoma
ACRAL MELAOMA
✔️ develops on the soles of the feet or palms of the hand
✔️ always large in size (>6mm)
✔️ variable pigmentation
✔️ begins as a smooth surface; eventually ulcerates and bleeds
