Dermatology: Clinical Cases of Rash

Question 1

Examination of general skin in psoriasis reveals?

Answer 1

Plaques on extensor surfaces, usually, e.g: extensor elbows, knees and shins

Question 2

Examination of scalp in psoriasis reveals?

Answer 2

Local adherent scale and erythema at the hairline

Question 3

Nail signs in psoriasis?

Answer 3

Nail dystrophy:

Pitting
Onycholysis - lifting up of nail plate that may discolour the nail
Subungual hyperkeratosis (thickening)
Longitudinal ridging

Question 4

Joint disease in psoriasis?

Answer 4

Psoriatic arthritis (joint swelling), e.g: tender hands

Question 5

Cause of psoriasis?

Answer 5

Multi-factorial disease with:

Genetic factors

Environmental factors inc. stress, drugs and infections

Question 6

What is the most common type of psoriasis and how does it present?

Answer 6

Chronic plaque psoriasis (psoriasis vulgaris) presents as:
Symmetrical, sharply dermarcated, scaly and erythematous plaques

Common sites affected are the extensors, scalp, sacrum, hands, feet, trunk and nails

IMAGE 1

Question 7

What is the Koebner phenomenon?

Answer 7

Psoriasis develops in areas of skin trauma, e.g: a scratch mark or scar

Question 8

What is Auspitz sign?

Answer 8

Removal of surface scale reveals tiny bleeding points (dilated capillaries in elongated dermal papillae, which have come close to the surface)

Question 9

What is guttate psoriasis?

Answer 9

Multiple small scaly plaques that tend to affect most of the body, unlike psoriasis vulgaris (where extensors are mostly affected)

Lesions are conc. around the trunk, upper arms and thighs

Question 10

What is palmoplantar pustular psoriasis?

Answer 10

Chronic pustular condition affecting the palms and soles; characterised by thickened, scaly, erythematous skin that easily develops fissures

Question 11

What is erythrodermis (or widespread pustular) psoriasis?

Answer 11

Rare and is a generalised redness of the skin that can be fatal; it may be precipitated by, e.g: infections, alcohol, low Ca2+

Question 12

Co-morbidities of psoriasis?

Answer 12

Psoriatic arthritis, metabolic syndrome (obesity, hypertension, diabetes, dyslipidaemia), Crohn’s disease, cancer, depression, uveitis

Question 13

Why is life expectancy reduced by 4 years, in patients with severe psoriasis?

Answer 13

Increased CV risk (3x for MI)

Question 14

Topical therapies available for psoriasis?

Answer 14

Vitamin D analogues, e.g: calcitriol and calcipotriol

Coal tar

Dithranol

Steroid ointments

EMOLLIENTS

Question 15

Other, more specialised treatments available for psoriasis?

Answer 15

Phototherapy (narrowband UVB and PUVA)

Systemic treatments, such as immunosuppression and immune modulation (with targeted biologic agents)

Question 16

What is acne vulgaris and how does it develop?

Answer 16

Chronic inflammatory disease of the pilosebaceous unit; there is increased sebum production and poral occlusion

Bacterial colonisation of the duct occurs, by P. acnes, and this is followed by dermal inflammation

Question 17

Distribution of acne vulgaris?

Answer 17

Related to sites with the most sebaceous glands, i.e: face, upper back and chest

Question 18

Morphology of acne vulgaris?

Answer 18

Comedones - open (blackhead) and closed (whitehead)

Pustules and papules

Cysts

Erythema

Question 19

Secondary features of acne vulgaris?

Answer 19

Different types of scarring:
Atropic
Hypertrophic
Ice-pick
Texture changes

Question 20

Grading of acne?

Answer 20

Mild - scattered papules, putules and comedones

Moderate - numerous papules and pustules along with mild atrophic scarring

Severe - cysts, nodules and significant scarring

Question 21

First-line therapies for acne vulgaris?

Answer 21

Topical agents, e.g: keratolytics (benzoyl peroxide) or topical retinoids (isotretinoin)

For inflammatory acne, topical antibiotics are used, e.g: erythromycin or clindamycin

Question 22

Second-line therapies for acne vulgaris?

Answer 22

Low-dose oral antibiotic therapy

Question 23

Third-line therapies for acne vulgaris?

Answer 23

Oral retinoid drugs, e.g: oral isotretinoin, if:
All other measures have failed
Nodulocystic acne with scarring
Severe psychological disturbance

Question 24

What are retinoids?

Answer 24

Synthetic vitamin A analogues that affect cell growth and differentiation

Question 25

Side effects of oral retinoids?

Answer 25

Inital aggravation of acne Very teratogenic - person must be on oral contraceptive or not sexually active (pregnancy test before and monthly during treatment)

Question 26

What is rosacea?

Answer 26

Common inflammatory rash predominantly affecting the face, part. nose, chin, cheeks and forehead Onset is normally in middle-ages and is more common in women

Question 27

Describe the rash in rosacea

Answer 27

Papules, pustules and erythema but no comedones (i.e: this is NOT a disease of the pilosebaceous units)

Question 28

Triggers of rosacea?

Answer 28

Exacerbated by sudden changes in temp, alcohol and spicy food

Question 29

Other symptoms of rosacea?

Answer 29

Rhinophyma (enlarged nose) | Conjunctivitis/gritty eyes

Question 30

Management of rosacea?

Answer 30

Reduce aggravating factors, e.g: dietary triggers, sun exposure and AVOID TOPICAL STEROIDS (can worsen the skin) Topical therapies, e.g: metronidazole, to reduce the demodex mites Oral therapies, e.g: long-term oral tetracycline and, if severe, isotretinoin (low dose) Vascular lasers for telangiectasia Surgery/laser shaving for rhinophyma

Question 31

Characteristics of lichenoid eruptions?

Answer 31

Damage and infiltration between the epidermis and dermis

Question 32

Most common types of lichenoid eruptions?

Answer 32

Lichen planus Lichenoid drug eruptions, e.g: ACE inhibitors (normally, a delayed reaction), statins, etc

Question 33

Clinical presentation of lichen planus?

Answer 33

Violaceous (pink/purple), flat-topped shiny papules typically affecting volar wrists/forearms, shins and ankles Wickham's striae (fine, white lace pattern on papule surface and on the buccal mucosa) Intensely pruritis

Question 34

Occurrence of lichen planus?

Answer 34

Tends to occur in middle age and lasts around 12-18 months before burning out

Question 35

Treatment of lichen planus?

Answer 35

``` Treat symptomatically: Topical steroids (if extensive, oral) - these should be potent/very potent ```

Question 36

How to differentiate between bullous pemphigoid and pemphigus?

Answer 36

Bullous pemphigoiD: Split is Deeper, through DEJ PemphiguS: Split more Superficial, intra-epidermal

Question 37

What is Nikolsky's sign?

Answer 37

Top layers of the skin slip away from the lower layers when slightly rubbed; this indicates a PLANE OF CLEAVAGE WITHIN THE EPIDERMIS , i.e: when the skin is rubbed, exfoliation of the outer layers can occur Present in Pemphigus vulgaris and Toxic Epidermal Necrolysis, but not in bullous pemphigoid

Question 38

Clinical presentation of bullous pemphigoid?

Answer 38

Localised to one area/widespread on the trunk and proximal limbs There are large, TENSE, BULLAE on an erythematous base; these can burst and leave erosions that do not scar However, early in disease, there may be urticated itchy plaques rather than bullae Nikolsky sign (negative) and mucosal lesions are unlikely

Question 39

Clinical presentation of pemphigus vulgaris?

Answer 39

Flaccid vesicle/bullae (thin-roofed) typically affecting the scalp, face, axillae and groin Lesions rupture to leave raw areas (infection risk) Nikolsky sign +ve and mucosal involvement is very common, e.g: eyes, genitals

Question 40

Prognosis of pemphigus vulgaris?

Answer 40

Chronic self-limiting course but the duration varies from months-years Most patients achieve REMISSION on treatment within 3-6 months

Question 41

Difference between mortality of pemphigus and bullous pemphigoid?

Answer 41

If untreated, pemphigus has a very high mortality Bullous pemphigoid has much lower risk

Question 42

Investigations for pemphigus or bullous pemphigoid?

Answer 42

Skin biopsy with direct immunofluorescence Indirect immunofluorescence

Question 43

Treatment of pemphigoid and pemphigus?

Answer 43

Systemic steroids Other immunosuppressive agents Topicals, such as emollients, topical steroids, topical anti-sepsis/hygiene measures IN PEMPHIGOID - tetracycline antibiotics