5. Common Skin Conditions Flashcards
1
Q
Dermatitis/eczema:
Acute vs Chronic
A
- “Inflammation of the dermis”
- Acute: erythema (redness), itching, oedema, vesicles, weeping
- Chronic: Skin thickening (‘lichenification’)
2
Q
Types (3) of Dermatitis:
A
- Atopic Dermatitis:
- Caused by genetic (filaggrin mutation) & environmental factors
- Atopic eczema linked to asthma & hay fever etc
- Affects 15-20% of children, with 80-90% resolved by teens, while 10% continue into adulthood
- Scalp -> Face -> Flextures as child ages - Irritant Contact Dermatitis:
- Due to contact with irritant e.g. detergents, solvents, workplace products, water, saliva etc
- Amount & strength of irritant is important
- Need to pass a threshold of exposure to occur - Allergic Contact Dermatitis:
- Due to an allergic reaction to allergen in contact with the skin (Type 4 hypersensitivity)
- Substances that can cause dermatitis include nickel, hair dyes, topical medications etc
3
Q
Treatments: Emollients
A
- Prevents water loss from skin & allergen development
- Repairs epidermal barrier
- Greasy: “Emulsifying ointment & Fatty cream”
- Lighter: Cetomacrogol with glycerol
4
Q
Treatments: Steroids Mild: 1x Moderate: 2-25x Potent: 100-150x Ultrapotent: 600x
A
- Mild: 1% hydrocortisone
- Moderate: Clobetasone butyrate
- Potent: Betamethasone valerate
- Ultrapotent: Clobetasol propionate
- Apply once daily using fingertip unit for hand (0.5g)
- Diluting a steroid by half does not alter its efficacy or potency
5
Q
Treatments: Topical immunomodulators
A
- Calcineurin inhibitors (Pimecrolimus & Tacrolimus) are non-steroids so can be used around eyes & eyelids
- Do not have problems associated with topical steroids
6
Q
Treatments: Other (for dermatitis)
A
- Systemic steroids
- Phototherapy
- Second line agents e.g. Methotrexate, Ciclosporin, Azathioprine
- Biological agents
- Janus kinase inhibitors
7
Q
Psoriasis:
A
- Affects 1-2% of population
- Genetics & environment important (post strep throat, medication)
- Any age but peaks at 15-25 & 50-60 years
8
Q
Types (5) of Psoraisis:
Sites of involvement
A
- Chronic Plaque Psoriasis: Red scaly plaques often on elbows/knees
- Guttate Psoriasis: “Rain drops”, can occur after strep sore throat
- Generalised Pustular Psoraisis
- Localised Pustular Psoriasis: Palms & Soles
- Erythrodermic Psoriasis: Skin failure
Found at scalp, nails, umbilicus, axilla
9
Q
What worsens Psoriasis?
A
- Stress
- Streptococci infection leads to guttate psoriasis
- Drugs such as systemic & potent topical steroids, lithium
- HIV/AIDS
10
Q
Psoriasis associated conditions
A
- Psoriatic arthritis
- Coronary artery
- Mortality, vascular disease
11
Q
Treatments for Psoriasis
A
- Topical therapy:
- Salicylic Acid
- Steroids
- Coal tar
- (Dirthanol)
- Calcipotriol
- Combination - beta + calcipotriol - Phototherapy
- Systemic therapy:
- Methotrexate
- Ciclosporin
- Acitretin (requires contraceptive for 3 years after use)
- Biologics: TNF-α (adalimumab)
- Interleukin 17 (secukinumab)
12
Q
Acne
- Pathogenesis (3)
- Aetiolgy (3)
A
Chronic inflammatory skin condition affecting face, neck, shoulders, chest & back
- Disorder of the pilosebaceous gland
- Blockage & rupture of the pilosebaceous duct
- Rupture of comedones involves inflammatory response & scarring
- Androgen-induced seborrhoea - excess grease
- Comedone formation - blackheads & whiteheads
- Cutibacterium acnes - colonisation of pilosebaceous duct
13
Q
Factors that may modify (aggravate) acne
A
- Hormones
- Medicines: Corticosteroids, anabolic steroids, lithium, cyclosporin
- Diet (weak evidence)
14
Q
Acne vs Rosacea
A
- Rosacea is indicated with redness, flushing, papule & pustules but NO comedones
- Gritty eyes
15
Q
Treatments for Mild Acne
A
Topical treatments:
- Benzoyl peroxide
- Azelaic acid
- Antibiotics (clindamycin) in conjunction with other topical agent
- Retinoids (adapalene, tretinoin)
- Apply to all of the face for 3 months (minimum)
16
Q
Treatments for Moderate Acne
A
Topical treatment + Oral treatment:
- Antibiotics e.g. doxycycline, erythromycin
- Hormones e.g. cyproterone + ethinyloestradiol
- Treat for at least 3 months
17
Q
Treatment for Severe Acne
A
Isotretinoin
- Effective but has major adverse effects e.g. teratogenic, dry skin, photosensitivity, depression - Requires ~6-9 months treatment
- Consider in mild acne as psychological distress can be severe
18
Q
Bacterial skin infections - impetigo
A
- Acute superficial skin infection that affects mainly children
- Golden crusted lesions
- Caused by S. aureus
- Associated with atopic dermatitis, scabies & skin trauma
- Clinically diagnosed with swab (microscopy, culture & sensitivities)
19
Q
Treatment of impetigo
A
- Topical antiseptic agents - hydrogen peroxide cream
- Never use topical antibiotics - encourages resistance
- Use oral antibiotics if extensive
20
Q
Fungal infections (4)
- Diagnosis?
- Differential diagnosis
A
- Tinea capitis: Can arise from animal fungus e.g Trichophyton verrucosum
- Tinea corporis (ringworm): itchy, red, scaly with a sharp edge
- Tinea pedis (athletes foot): well demarcated, red, itchy peeling skin caused usually by Trichophyton rubrum
- Onychomycosis (nail): clinically white/yellow, thickened, crumbly with source of tinea infection elsewhere
Diagnosis is usually done via skin scrapings/nail clippings before treatment
Differential diagnosis:
- Dermatitis
- Psoriasis
- Mixed infection (macerated web spaces)
- Bacterial infection - nail
21
Q
Treatment of fungal infections
A
Topical:
- Miconazole, clotrimazole,
- Terbinafine
- Apply for once/twice daily until rash has resolved then for 3-5 days after
Systemic:
- Terbinafine
- Itraconazole (many drug interactions)
22
Q
Fungal infections: Pityriasis versicolor
- Basic info
- Treatments
A
- Due to yeast Malassezia furfur
- Seen in young adults (trunk)
- Red, brown, plate patches
- Causes dyspigmentation of the skin
Treatments:
- Ketaconazole shampoo: Body scrub
- Creams: Terbinafine, clotrimazole/miconazole
- Oral: Itraconazole
23
Q
Fungal infections: Pityriasis capitis /Seborrhoeic dermatitis (dandruff)
- Basic info
- Treatments
A
- Caused by Malassezia furfural yeast
- Babies: Cradle cap
- Adults: Scalp, eyebrows, behind ears, upper chest
- Do not requires skin scraping
Treatments:
- Topical: Miconazole-hydrocortisone cream, Ketaconazole shampoo
- Systemic: Itraconazole
24
Q
Viral infections - Herpes simplex (cold sores)
A
- Type I usually causes oral & facial infections
- Type II usually causes genital & rectal infections (anogenital herpes)
- Primary infection in infants & young children with virus becoming dominant in nerves (recurrence)
- Recurrence can be triggered by trauma, infection, sun exposure, hormones, stress etc
- Diagnosis: history of discomfort & itch with no rash then vesicles appear
- Examination: Vesicles on red base & enlarged local lymph nodes
- Normally heals in 7 - 10 days
25
Treatments for Cold Sores
- Oral antiviral agents: Acyclovir, Valaciclovir
| - Topical antivirals
26
Arthropod infections - Head lice (Pediculosis humanis capitis)
- Small insects that infect human scalp, feed on human blood, cling to hair & rapidly moves
- Common problem for children aged 4-14 years
- Itchy scalp which may take several weeks to develop
- Heavy infestation can lead to dermatitis, impetigo & swollen lymph nodes
27
Treatment for head lice
- Phenothrin shampoo
| - Dimeticone (suffocants)
28
Arthropod infections - Scabies (Sarcoptes scabiei)
- Mites burrow underneath top layer of skin & breed, lay eggs, poo & die
- Very itchy
- Most patients only have ~10 mites - carefully examine finger webs, hands & wrists
- Rash due to hypersensitivity to dead mites, faeces
- Secondary infection common
29
Treatment of Scabies
- Topical: Permethrin cream
- Oral: Ivermectin
- Apply to all of the skin inc face in elderly & young
- Treat all household contacts at once
30
Arthropod infections - Others
- Public lice
- Ticks
- Insects
- Bed bugs
31
Papular Urticaria
- Grouped papule that are very itchy & last for days
| - Caused by: Fleas, mosquitoes, mites etc
32
Sunlight: UV radiation damages?
- Damages melanocytes & keratinocyte nuclei
| - Leads to DNA damage
33
Acute effects of UV radiation
Sunburn:
- 2-6 hours of exposure & peak at 12-24 hours
- Pain swelling
- Blistering (Severe)
- Erythema
34
Chronic effects of UV radiation
- Photoageing
- Dyspigmentation
- Actinic keratoses
- Skin cancer
35
Skin cancer - 3 types
UV damage to epidermis:
- Keratinocytes: Squamous cell carcinoma (1)
- Melanocytes: Melanoma (2)
- Basal cell carcinoma (3)
36
Melanoma
- Basic info
- Common sites (NZ)
- Tell tale signs
- NZ has highest rate in the world
- Maori & pacific peoples have lower chance of getting melanoma - often have more serious melanomas
- Men: Back ~40%
- Women: Legs ~35%
- Change in pigmented lesion is most important clue
37
Squamous cell carcinoma
| - Basic info
- Malignant proliferation of keratinocytes
| - Can spread
38
Basal cell carcinoma
| - Basic info
- Most common
- Slow growing
- Spread locally
- Curable
39
Pharmacists role in skin cancer
- Advise patients on the correct use of sunscreen
| - Nicotinamide 500 mg bd
40
Nicotinamide in cancer prevention
- Reduces UV induced immunosupression
