Dermatology Flashcards
A 45-year-old business executive presents with a 2-year history of a chronic, scaling erythematous rash with widespread confluent patches over the trunk as well as the scalp, natal cleft, elbows and knees.
(a) What is the likely diagnosis?
(b) Name 3 clinical features on history and examination that would support your diagnosis.
(c) Name 3 treatment options that could be considered if topical therapy had been ineffective.
(d) List one major adverse reaction that could complicate each of the treatment regimens you have considered in the last question.
A. Chronic plaque psoriasis
B. Middle aged onset, persistent for 2 years (unusual for atopic dermatitis or other dermatoses), scaling of erythematous patches, scalp + extensor surface + gluteal cleft distribution
C/D:
PUVA/UVB: increased risk of skin malignancy, folate deficiency
Oral methotrexate: lung toxicity, GI upset, teratogenicity, hepatotoxicity, skin rash
Oral acitretin (retinoid): mucosal irritation, hepatotoxicity, photosensitivity, hyperTG
Oral cyclosporin A: gingival hypertrophy, hirsutism, cardiometabolic effect, nephrotoxicity
Anti TNF: TB/hepatitis reactivation, heart failure, neoplasm, anaphylaxis
A 29-year-old patient with leukaemia, recently given chemotherapy, was admitted with mucosal erosion and erythematous macular eruption affecting mainly his accrual area but also his trunk and limbs. On closer examination, there were central blisters in some of the involved areas.
(e) What is the most likely diagnosis?
(f) How do you confirm the diagnosis?
(g) List 3 measures that you will do in terms of management.
e. Bullous sweet syndrome a/w AML. Vesicles and flaccid bulla overly erythematous/violaceous plaques
b. Blood: high ESR, CRP, WBC >8 with >70% neutrophils. Punch biopsy: dense neutrophilic infiltrate w/o leukocytoc clastic vasculitis
g. Supportive: secure airway, fluid resuscitation, wound dressing, watch out for eye involvement and superimposed infection
Management of underlying leukemia
Specific: systemic steroids (“classically a/w dramatic response)
A 56-year-old lady was admitted in with one-week history of generalized erythroderma.
(a) Name three possible causes of her condition.
(b) Name three potential complications.
(c) List the investigations one should perform upon her admission.
a. psoriasis, drug allergy, eczema, TEN, pemphigus
b. fluid and electrolyte imbalance, high output cardiac failure, thermoregulatory disturbance, infection (esp secondary sepsis with SA), hypoalbuminemia
c. CBC/D, LFT, RFT, glucose, blood smear (sezary syndrome), wound swab x culture/sensitivity. Skin biopsy: often non specific
A 52-year-old man presents with fever and chills for 2 days. Examination reveals generalized and uni- form redness and scaling involving the skin. There are enlargement of the regional lymph nodes and oedema of the ankles.
(a) Name three possible causes for his skin condition.
(b) What are the investigation?
(c) How are you going to manage this patient?
a. Erythroderma due to psoriasis, atopic dermatitis, drug reaction, TEN, pemphigus
b. CBC/D, L/RFT, glucose. Blood smear x sezary syndrome, wound swab x C/ST, skin biopsy
c. Supportive tx with fluids, correction of electrolyte disturbance, nutritional support. Symptomatic tx by topical steroid, oral antihistamine. Tx complications: hypoalbuminemia/heart failure accounting for ankle edema and any infection.
A 78-year-old patient with history of stroke, diabetes mellitus on insulin and hypertension is admitted for a widespread progressive blistering eruption associated with itchy rashes and multiple eroded areas for 3 weeks. On examination, there are multiple large blisters and erosions over all 4 limbs and occa- sionally found on the trunk in the background of a generalized urticarial-like eruption. Oral mucous membrane is not involved. Initial blood investigations showed eosinophilia and random glucose of 14 mmol/L.
(a) Name the diagnosis and two differential diagnoses.
(b) What investigations should be taken?
(c) What are the main principles of management?
(d) What concomitant management is important if the condition is deemed necessary to use sys- temic corticosteroid?
a. Bullous pemphigoid. ddx: paraneoplastic pemphigoid, pemphigus vulgaris, EM
b. CBC/D, L/RFT, blood glucose as baseline. Punch Bx at edge of ulcer x hiustology, IF. Serum x indirect IF, anti skin ab (anti BP 180/230, anti desmoglein). Wound swab x C/ST.
c. Supportive (electrolytes, wound care, treat any infection), systemic corticosteroid in view of widespread involvement. Taper after blister formation and start steroid sparing agent as maintenance. Glycemic control.
d. Watch out for worsening of glycemic control. Likely need increased dosage of insulin. Long term use a/w metabolic sequelae. Should start steroid sparing therapy as soon as condition allows to taper steroid. Also need to optimize HTN, cardiovascular RFs. R/o infection before starting steroid.
A 44-year-old male patient is admitted for a generalized painful pustular rash for 2 days. Physical ex- amination showed a widespread intense erythematous tender scaly eruption with pinpoint pustules on trunk and limbs. The patient appears lethargic with fever (39.5°C) and initial investigation reveals neu- trophilia.
(a) What is the diagnosis and differential diagnosis?
(b) What additional physical signs should be sought to establish the diagnosis?
(c) What investigations should be taken?
(d) What are the precipitating factors of this condition?
(e) What is the mainstay of treatment?
a. Generalized pustular psoriasis. ddx: AGEP, subcorneal pustular dermatosis, IgA pemphigus
b. Auspitz sign (punctate bleeding when psoraitic scale is scraped off), thick silvery scales, look for other forms of psoriasis (e.g. chronic plaque psoriasis at extensor aspect)
c. CBC/D, L/RFT, CaPo4 (a/w organ failure), BG, blood culture. Wound swab x C/ST. Skin Bx x histology.
d. Steroid withdrawal
e. Immunosuppression by methotrexate, cyclosporine, anti TNF, anti IL17A
SSSS features
- Occurs in < 5y; usually in those with serious illness
- Due to exfoliative toxin A/B cleaving desmoglein 1
- Affects upper epidermis –> nikolsky sign+ve, flaccid blisters with erosion
- Low mortality
Features of erythema nodosum
Biopsy features
- Septal panniculitis w/o vasculitis
- A/w pTB, step, OCP, IBD, sarcoidosis, drug hypersensitivity
- Usually in bilateral shins +/- arms, face, seldom on trunk
Necrotizing fasciitis features
- Common in limbs/perineum
- Due to strep or mixture of aerobic and anaerobic
- Cx of cutaneous infection or preceding surgery
- Fever, systemic toxicity, severe local pain, marked oedema, tenderness
- Numbness = nerve involvement
- Oedema, pain beyond apparent limit of infection
- Violaceous skin, bulla, crepitus, gangrene
- Rapid progression
- Surgical exploration + IV Abx (gentamicin, fortum)
Feature of erythema induratum
- Recurrent painful nodules in the lower legs: lobular panniculitis with vasculitis can recur
Features of erythema multiforme
- Typical and atypical targets, Koebner, spread from limbs to trunk
- Systemic upset as prodrome
- Mucosal involvement common esp oral
- Associated with HSV, M. pneumoniae, sulpha drugs
- Self-limiting in 2 weeks, Tx of underlying cause does NOT help
- Steroid for symptomatic Tx only
Pyoderma gangrenosum
Appearance
A/w disease
Bx
Mx
- Painful nodule or pustule breakdown to form progressively enlarging ulcer
- Irregular/ purplish border
- a/w IBD, arthritis, CTD, gammopathy, haematological malignancy, bechet
- Bx: non specific, only to r/o alternative
- Mx: topical steroids, systemic steroid/cyclosporine
Which of the following is a correct correlation between the morphological description and the underlying skin lesion
A. Morbiliform — drug eruption
B. Nodular — impetigo
C. Pigmented — herpes zoster
D. Vesicular — melanoma
E. Weepy — psoriasis
A. Morbilliform: drug eruption
Impetigo: bullous/papules
Herpes zoster: vesicle in dermatomal distribution
Melanoma: pigmented nodular
Psoriasis: scaly plaque
A 35-year-old man with history of malignant lymphoma 2 years ago, still on oral immunosuppressants. He presented with fever and generalised blistering erythematous rash over limbs and trunk one fine day. The oral mucosa was not involved. What is the diagnosis?
A. Paraneoplastic pemphigus
B. Bullous pemphigoid
C. Steven-Johnson syndrome
D. Eczema herpeticum
E. Disseminated herpes zoster infection
Ans: E (immunosuppression)
A: typically affects mucosa
B: too young, already on immunosuppressant
C: no new drug
D: no prior eczema
A 60-year-old female presented with fever and progressive pustular eruption on trunk and proximal limb. Amoxicillin and clavulanate given after drainage of an abscess in her right arm 1 week ago. She had a history of diabetes mellitus, hypertension, renal impairment, on insulin & stable hypertension for years. There was no history of skin disease. On physical examination, there were crops of pustules on erythematous and oedematous skin on trunk and arms. Some of those lesions developed into erosions. There were no mucosal lesions in oral cavity and genital area. What is the diagnosis?
A. Acute generalized exanthematous pustulosis
B. Disseminated herpes zoster
C. Eczema herpeticum
D. Generalised pustular psoriasis
E. Steven-Johnson syndrome
A: 90% due to drugs, commonly antibiotics
