week 8 clincial therapeutics

Dermatitis case: 18-year-old student with a relapse of dermatitis during exams

  • Patient: Jay Bieber, 18, first year of university; has had dermatitis since childhood but a recent relapse with stress (exam period)
  • Affected areas: arms, trunk, and face; symptoms likely itchy inflammation
  • Allergies/history: allergic to cats; hay fever with pollen; asthma since childhood
  • Dispensing history (current meds): Symbicort (budesonide/formoterol), terbutaline; loratadine tablets; beclomethasone nasal spray (in spring for hay fever)
  • New prescription: hydrocortisone 1% cream; betamethasone valerate 0.2% cream
  • Question 1: Which is more potent, hydrocortisone or betamethasone valerate? → Betamethasone valerate is more potent
  • Practical note: hydrocortisone used for facial eczema because milder and less occlusive; betamethasone valerate used on the body (trunk, arms, etc.)
  • Question 2: Where to apply which steroid? Hydrocortisone first on the face; betamethasone valerate on body
  • Type of dermatitis? Atopic dermatitis (history of asthma and hay fever)
  • Atopic triad: hay fever, asthma, itch; linked to IgE-mediated hypersensitivity; predisposition to atopy
  • Triggers identified: stress; cat exposure; pollen (hay fever)
  • Counseling points: advise avoidance of triggers (cats, pollen, stress management)
  • Repeat prescription: usually not issued with repeats unless the prescriber marks “x” for repeats; monitor frequency of use
  • Affected areas: arms, face, trunk; coverage considerations for corticosteroids
  • Coverage rule concept: do not assume “cover only affected areas”; treat all affected regions appropriately
  • Coverage calculation example: to cover trunk, back, arms, and face, more product is needed than just hands; ask about exact areas to estimate amount
  • Rule of application: apply to all affected areas; petroleum-based creams not discussed; emphasize precise targeting
  • Fingertip unit (FTU) concept: one fingertip unit is enough to cover two adult hands (rule of thumb)
    • FTU definition: squeeze tube up to the first creases of the finger
    • Implication: with trunk and back involvement, more cream will be required; quantify area to avoid under-treatment or wastage
  • Practical assessment: you must tailor application to exact affected areas rather than vague instruction such as “the affected area”
  • Management principles: corticosteroid + emollient as cornerstone therapy
  • Emollients: fragrance-free, non-irritating moisturisers; apply after showering and/or as needed to maintain skin barrier
  • Hydrocortisone counseling points: apply to the trunk and arms (targeted areas); dosing: twice daily; aim to reduce itch and inflammation; avoid overuse
  • Efficacy focus: specify the exact affected areas rather than generic guidance; ensure patient knows precisely where to apply
  • Adverse effects of topical corticosteroids: generally minimal with low-potency hydrocortisone; potential skin thinning with long-term use of potent steroids; monitor for irritation
  • When to worry about side effects: thinning of skin when potent steroids used long-term; counsel on signs and skin checks
  • Role of antihistamines: loratadine (second-generation) usually non-sedating; first-generation antihistamines (e.g., older agents) cause sedation but may help with nocturnal itch
  • Case-specific antihistamine use: loratadine may not directly treat itch but can help with allergic rhinitis symptoms; first-generation antihistamines can aid sleep in some patients
  • Treatment approach for atopic dermatitis: first-line is topical corticosteroids + moisturisers
  • When to add antihistamines: for sleep disturbance due to itch; not primary itch control
  • Distinction: dermatitis vs ringworm
  • Task: differentiate between ringworm (tinea) and dermatitis; ringworm is fungal; dermatitis is inflammatory/atopic
  • Ringworm features: border is clearly defined or raised; center may be flat; ring-like lesion with erythematous border; central clearing
  • Dermatitis features: more diffuse, poorly defined edges, itch, dry scaly patches; may involve multiple areas
  • Treatment options for fungal infections (dermatophytes) – first-line option:
    • Terbinafine 1% cream (topical) as first-choice therapy (fungicidal)
    • Compared with azoles (e.g., clotrimazole) which are fungistatic
    • Typical duration discussed: terbinafine often started for 1–4 weeks depending on site and severity; topical use often 1–4 weeks for skin; ensure full course to prevent relapse
    • Terbinafine works by inhibiting squalene epoxidase, leading to fungal cell death (fungicidal)
    • Azoles (e.g., clotrimazole) inhibit ergosterol synthesis; fungistatic
  • Practical notes on topical antifungals:
    • Terbinafine is favored for straightforward tinea corporis/cruris/pung skin infections due to fungicidal action
    • Clotrimazole and other azoles are alternatives when terbinafine is contraindicated or not tolerated
    • Tirbanibulin (novel topical antifungal) considerations: not recommended in children under 12 years; limited age use; monitor for safety
  • When to escalate to systemic antifungals:
    • If scalp (tinea capitis) or extensive/difficult infections or failure of topical therapy
    • Involvement of nails (onychomycosis) or tinea unresponsive to topical therapy
  • Important lifestyle tips for fungal infections:
    • Hygiene practices: keep skin dry, avoid sharing towels or clothing, wash affected areas daily, and avoid skin-to-skin contact until treated
    • Contagion awareness: fungal infections are contagious; hygiene reduces spread
  • Distinguishing features recap:
    • Ringworm: well-demarcated borders, ring-shaped lesions with central clearing
    • Dermatitis: diffuse or patchy red itchy areas without a clear ring-like border
  • Additional targeted notes:
    • When choosing antifungals for tinea, consider potency, duration, and risk of resistance; terbinafine tends to be fungicidal and often preferred for uncomplicated cutaneous fungal infections
    • If a topical agent is not improving symptoms after a full course, reassess diagnosis and consider alternative therapies or systemic treatment

Acne case overview and management (Task five and task six)

  • General epidemiology of acne:
    • Acne is more common in males; age groups affected include puberty through young adulthood; in males often resolves by their twenties; in females it may persist into the forties
  • Common anatomical sites: face, back (upper), neck, shoulders, chest due to high density of sebaceous glands
  • Common patient questions and myths:
    • “Washing my face more will get rid of acne?” → No; over-washing worsens irritated/dry skin; can trigger more skin irritation
    • “Certain foods worsen acne?” → No strong evidence linking diet to acne; acne is not infectious; acne is not caused by food
  • Types of acne by severity:
    • Mild: small papules, some whiteheads/blackheads; confined to the face
    • Moderate: involvement of additional areas (jawline, back), more inflammatory lesions
    • Severe: significant inflammation with scarring risk
  • General treatment approach by severity:
    • Mild acne: topical therapies such as benzoyl peroxide (Benzac AC) and azelaic acid; topical retinoids (e.g., tretinoin) may be added
    • Moderate acne: add systemic therapy such as doxycycline 50 mg daily; in females, consider combined oral contraception to help regulate hormones and reduce sebum production
    • Severe acne: isotretinoin (oral retinoid) reserved for severe or refractory cases; extensive scarring risk; can be highly effective but carries significant risks and monitoring requirements
  • Doxycycline role and dosing (for acne, not infection):
    • Typical dose for acne: 50 mg daily (lower than infectious dose; anti-inflammatory effects help reduce lesion formation)
  • Female-specific considerations:
    • Combined oral contraception can be used to complement acne treatment during moderate disease
  • Isotretinoin (oral retinoid) for severe acne:
    • Category: Class X (pregnancy category; teratogenic)
    • Warrant and monitoring: Must be prescribed under a dermatologist with a formal patient management protocol (birth control/warrant program) and a monitoring plan
    • Contraception counseling: Two forms of birth control are required while on isotretinoin; continue consistent contraception after stopping for a defined period
    • Common adverse effects: extremely dry skin/lips; mood changes; potential depression and suicidality risk → requires psychosocial support and monitoring