Derm update 2024 - Dr Alicia Thornton

Psoriasis

Background

• 2% prevalence

• Less common with darker skin

• 10% patients are < 10 years old

• Related to metabolic syndrome

• Relapsing / remitting

Predisposing

• Strep infection

• Family history

• Skin Trauma

• Psychological or physiological stress

• Medications

  • Lithium, Interferon B, B blockers, Corticosteroid withdrawal, Anti-TNF

• Alcohol

Types

• Guttate

• Chronic plaque

• Palmplantar

• Flexural

• Genital

• Sebopsoriasis

• Nail

• Pustular

Treatment

• Topical steroids

• Wet dressings once or twice daily

• Bland emolients (cream not ointment)

• Keratolytics (low concentration salicylic acid 2 to 3%)

• Coal tar creams

• UVB phototherapy

• Systemic agents

  • Methotrexate, Cyclosporine, Acitretin, Newer

• Biologics

  • Adalimumab 4 years +

  • Ustekinumab 6 years +

Granuloma Annulare

Background

• Common in children

• Often asymptomatic

Variants

• Localised

• Generalised on trunk + extremities

• Subcutaneous - nodules - pretibial, hands, buttocks, scalp, feet,

• Perforating - crusting, ulcers, dorsal hands and fingers

Predisposing

• Family history

• Diabetes

• Infections

• Vaccinations

• Skin trauma

Treatment

• Potent steroids (Diprosone 0.05% ointment - better penetration

• Occlusion

• Steroids then white cotton sock then spray bottle with water over affected areas

• Tubifast cut to size

• Intralesional steroid injections 6 to 8 weekly

• Pimecrolimus or tacrolimus 0.1% compounded ointment

  • Can be useful on face

  • Use when lesions have started to thin after potent steroids

• UV phototherapy

• Systemics agents - Plaquneil, Pred, Minocycline, Isoretinoin, Dapsone, MTX

Prognosis

• 50% resolve spontaneously by 2 years, more likely if localised lesions only

Pityriasis Roasea

• Extensive exanthem

• Preceded with herald patch 1 to 2 weeks

• Age 10 to 35

• Common in Autumun and Spring

• Linked to HHV6 and 7 - often asymptomatic

• Pink palpable plaque with trailing collarette of scale

• Christmas tree distribution (followes lines of cleavage)

• Self resolves 6 to 14 weeks

• Mid-potency steroids and emolients

• Erythromycin 2 to 4 weeks

• UVB or sun exposure

• Antihistmamine

Pityriasis Lichenoides

• Clonal T- cell disorder

• Thought to be triggered by virus

• Recurrent crops of spontaneous regressing scaly papules

• Can be itchy or not, can be sensitive and stingy

• Range from acute form

• Acute to chronic PLEVA / PLC

• Rare cases of progression to cutaneous T cell lymphoma

• 6 to 12 monthly monitoring

• Mid-potency topical steroids, coal tar, erythromycin, UVB, short course prednisolone, methotrexate

Lichen Nitidus

• Fine pin point papules skin coloured

• Flexural surfaces of arms

• Subtype lichen planus

• Topica lsteroids

Lichen Striatus

• Self limited dermatitis in Blaschkoid unilateral distribution

• Age 4 months to 15 years

• Sudden onset

• Regressed over 6 to 12 months

• Dut to somatic mosaicism +/- viral trigger

• Nail involvement

• Usually asymptomatic

• Topical steroids don’t generally work

Vitiligo

• Acquired autoimmune depigmentation condition

• Loss of melanocytes

• 2% prevalence

• Bimodal < 10 and >30 years

• Predisposing

  • Family history

  • Autoimmunity

  • Koebnerisation

  • Metastatic melanoma + treatment

• Consider skin biopsy

• FBC, UEC, LFT, Iron studies, CRP, ESR

• B12, ANA, ENA, TFT + antibodies, coeliac serology, BSL, Urine glucose

• HBV, HCV, HIV, QF gold, Strongyloides

• Chronic and prone to relapse

• Support groups

• Treatment

  • Camouflage

  • Sun protection

  • Topical steroids e.g. Methylprednisolone 0.1% daily (Advantan) alternate weeks

  • Daivobet ointment

  • Compounded tacrolimus 0.03% or 0.1%

  • UV phototherapy

  • Topical JAK inhibitors

  • Systemic agents

  • Depigmentation therapies