CBL - Acute Skin Rash, Psoriasis & Cutaneous Drug Reaction

Question 1

68 year old male, known hypertension on multiple recently revised medications, recent holiday insect bite and cellulitis, treated with antibiotics for 7 days. Known historical low grade psoriasis.

Developed inflammatory flat macular rash on trunk/limbs. Mildly itchy, symmetrical. Feels well.

Give 3 potential skin diagnoses for this patient [3]

Answer 1

1. Flare of pre-existing psoriasis
2. Cutaneous drug reaction to new anti-hypertensive or antibiotic for cellulitis
3. Scabies or insect bite reaction

Question 2

Describe the broad categories of medication induced skin eruptions [4]

Answer 2

1. Maculopapular rashes
   
   • caused by antibiotics
2. Photosensitive rashes
   
   • caused by diuretics, antibiotics
3. Severe idiosyncratic reactions e.g. Toxic Epidermal Necrolysis (TEN)
   
   • caused by antiepileptics, antibiotics
4. Urticarial reactions
   
   • caused by antibiotics, opiates, NSAIDs, ACE inhibitors

Question 3

Describe some patterns and distributions that might occur clinically in drug-induced skin eruptions [6]

Answer 3

1. Widespread, truncal
2. Urticarial, wheals, dermographism
3. Localised drug reactions, fixed drug eruptions
4. Mucosal involvement
5. Sun exposed- photosensitive reactions
6. Contact reactions to creams

Question 4

Describe the typical clinical features (signs and symptoms) of psoriasis [8]

Answer 4

1. well defined, erythematous (salmon coloured) scaly plaques
2. usually affects the extensor surfaces and scalp
3. ring shaped and symmetrical
4. nail pitting
5. onycholysis (nail lifting off surface of bed)
   
   • destructive nail arthritis sign of psoriatic arthritis
6. oil spotting
   
   • yellow/reddish discolouration of the nails
7. micropustules
   
   • marker of instability and psoriasis aggressiveness
8. psoriatic arthritis
   
   • painful inflammation of joints and surrounding connective tissue

Question 5

What are the main scoring systems for psoriasis? [3]

Answer 5

1. DLQI
   
   • disease life quality index
   • psychological marker
2. PASI
   
   • psoriasis area severity index
3. PEST
   
   • psoriasis epidemiology screening tool
   • excludes involved rheumatological pathology
   • used to exclude psoriatic arthropathy (psoriatic arthritis)

Question 6

In chronic plaque psoriasis, give a treatment ladder of therapies starting with the mildest to the more systemic and complex 3rd line treatments [5]

Answer 6

1. Topicals:
   
   • Emollients,
   • Corticosteroids,
   • Vitamin D Analogues,
   • Tar/Dithranol
2. Phototherapy
   
   • UVB,
   • PUVA
3. Systemics
   
   • Retinoids (acitretin),
   • Apremilast,
   • Dimethyl Fumarate
4. Immunosuppressives
   
   • Ciclosporin,
   • Methotrexate
5. Biologic immunosuppressives
   
   • Adalimumab,
   • Secukinumab,
   • Risankizumab etc.

Question 7

If a patient takes excess alcohol and has a history of previous treated tuberculosis, why are these significant for deciding systemic therapy for psoriasis? [2]

Answer 7

1. often liver toxic,
2. immunosuppressives can resurge pre-existing or unknown tuberculosis

Question 8

If the patient had a previous malignancy, in remission from 10 years ago, what would you need to know and how would that impact on treatment choices for psoriasis? [5]

Answer 8

1. Immunosuppression theoretically could cause recurrence, certain drugs higher risk
2. Need to find out what type of tumour was it, was it a high risk tumour, was it completely resected?
3. Consider non-immunosuppressive treatment
4. Liaise with Oncologist and surgeon.
5. Risks, benefits vs quality of life right now if severe psoriasis

Question 9

If the patient with psoriasis complains of joint pains, how would you assess this, what pattern might you expect to see of associated joint problems and what considerations in treatment might you have to give? [4]

Answer 9

1. small joint/digit arthritis
2. typical signs & symptoms:
   
   • swelling
   • redness
   • arthralgia
   • look for significant nail pitting
   • axial sacroiliac
3. certain drugs better for combination skin psoriasis and psoriatic arthritis
   
   • e.g. methotrexate
4. Anti inflammatories for joints
   
   • e.g. Naproxen

Question 10

What investigations and referrals might you make in a patient with psoriatic arthritis? [4]

Answer 10

1. inflammatory blood markers
2. plain film x-rays
3. autoantibodies e.g. ANA and Rheumatoid factor
4. consider PEST score assessment of joints and referral to Rheumatologist