Dermatology Flashcards
What is Nikolsy’s sign?
Slight rubbing of the skin removes the top layer.
Present in Staph Scalded Skin and TES
What is Staph Scalded Skin?
- Usually in infants and early childhood or immunocompromised adults.
- Prodome of fever, malaise, irritability sever skin tenderness
- Skin erythematous then starts to peel off
- Usually involves flexures
- Potentially life threatening
Exfoliative S. aureus toxin which targets granular layer of the skin causing an intraepidermal sterile blister.
Blood and blister cultures often negative. Infections with S.Aureus somewhere in the body but the toxins spread haematologically to cause the SSSS.
What are the differences between toxic epidermal necrolysis and staph scalded skin?
TEN:
- usually affects adults
- caused by drugs
- Histology - dermo-epidermal split, epidermal necrosis
- often involves mucosal surfaces
- Nikolsky sign present in some areas
- Treatment as per burn treatment ?IVIG
SSSS
- affects infants, children and immunocompromised adults
- Caused by toxin-producing S.Aureus
- Histology - granular layer split
- Does not affect mucous membranes
- Nikolsky’s sign present in seemingly uninvolved skin
- Perioral fissures and crusts
- Treatment with antibiotics and supportive care
What are Pastia’s lines?
Lines formed of confluent petechiae found in skin creases, esp antecubital fossa.
Occurs in patients with scarlett fever prior to appearance of the rash.
What is the prognosis for SSSS?
- Heals without scarring
- Improves 5-7 days
- Mortality 3%
What is mastocytosis?
Local of diffuse accumulation of mast cells in the skin +/- internal organs.
- Cutaneous (most frequent type in childhood)
- mastocytoma 10-30%
- urticaria pigmentosa 70-90%
- Diffuse cutaneous mastocytosis 1-3%
- Systemic
- Mast cells infiltrate organs
- Assoc with haematological malignancy
- Mast cell leukaemia
What is Darier’s Sign?
Skin becomes swollen, itchy and red with rubbing. Results from compression of mast cells which release histamine.
What drugs can be used to impove the symptoms of mastocytomas?
Antihistamines
Scalp hair loss + skin scaling =?
Tinea capitus.
Treat with oral antifungals for 1 month after taking a scraping and finding out what fungus is sensitive to.
Check close contacts for ? need for treatment.
Topical antifungals won’t be strong enough to heal condition, but may help to reduce transmission.
Treat with griseofulvin or terbinafine.
Can use itraconazole.
What is a kerion?
A scalp fungal infection together with a bacterial infection causing a boggy red plaque.
May commence oral antifungals immediately, plus take a swab. Also commence pronlonged oral antibiotics (eg erythromycin)
What is epidermolysis bullosa?
Group of genetically inherited defects in the skin basement membrane resulting in skin fragility.
Skin and mucosa separate from underlying tissues following mechanical trauma.
Many subtypes of EB. (Herlitz, non Herlitz, dominant, receessive)
One form of Herlitz EB associated with Pyloric atresia.
Investigation is skin biopsy for confirmation.
What is the clinical picture of subcutaneous fat necrosis of the newborn?
Assoc with
- birth asphyxia
- mec aspiration
- c sect
- cold exposure
Hypercalcaemia may occur as late as 4 months
High or inappropriate normal 1,25 dihydroxy Vit D
Suppressed PTH
What is the significance of maternal Anti-Ro/Anti-La antibodies to a pregnant woman?
Newborns can passively acquire neonatal lupus from a mother with anti-ro/anti-la antibodies. (15-20%)
Risk of heart block is two percent in the first baby, and in subsequent babies if previous does not have cutaneous neonatal lupus or heart block. Risk increased ten and five fold respectively if previous babies did have CNL or HB.
2008 Paper Q 97 Part 2
A ten-month-old boy presents with the facial rash as shown below. He has had dry skin on his cheeks for some weeks, and his parents have been applying moisturiser and Mometasone furoate 0.1%.
In addition to oral antibiotics, the most appropriate management now would be to:
A. add topical aciclovir.
B. add topical mupirocin.
C. add topical triclosan.
D. change to hydrocortisone 1% cream.
E. change to pimecrolimus cream.
D. Change to hydrocortison 1% cream
A five-year-old boy presents with multiple ulcerated skin lesions (as shown) with raised margins, which commenced as pustular lesions associated with fever a week prior to presentation. Pyoderma gangrenosum is confirmed by skin biopsy.
Which of the following is most likely to be associated with this skin lesion?
A. Chronic granulomatous disease.
B. Human immunodeficiency virus (HIV) infection.
C. Inflammatory bowel disease.
D. Pseudomonas septicaemia.
E. Systemic lupus erythematosis.
C. Inflammatory bowel disease
2007 Part 2 Q 22
A two-year-old girl returns from child care after an apparently ordinary day. When her mother undresses her for her bath she notices blood in the girl’s underwear. The mother examines the girl’s genital region and notices the findings in the photograph.
What is most likely the cause of the girl’s genital bleeding?
A. Accidental “fall astride” injury.
B. Congenital haemangioma of the labia.
C. Lichen sclerosis et atrophicus.
D. Sexual abuse.
E. Traumatic separation of labial adhesions.
A. Accidental “fall astride” injury.
A nine-month-old boy is seen in clinic with an eight week history of an itchy rash. Reddish-brown macules and papules are noted on his trunk and back as shown in photo one. He takes prophylactic cotrimoxazole for high grade vesicoureteric reflux but is otherwise well.
On examination, it is noted that stroking the lesions leads to erythema of the surrounding skin as shown below in photo two.
The most likely diagnosis is:
A. chronic urticaria.
B. drug reaction.
C. insect bites.
D. scabies.
E. urticaria pigmentosa.
E. urticaria pigmentosa.
2008 Paper 2 Q 62
An eight-year-old girl is referred for assessment of her chronic perineal irritation. A photograph of her genitalia is shown below.
Which of the following is the most likely diagnosis?
A. Child sexual abuse.
B. Lichen sclerosis et atrophicus.
C. Mucocutaneous candidiasis.
D. Perineal psoriasis.
E. Pinworm infestation.
B. Lichen sclerosis et atrophicus.
2006 Part A Q27
A previously well two-year-old boy presents to his general practitioner with tonsillitis and a macular red rash over his body. He is treated with oral Penicillin V. After two days he is admitted with a sudden onset of fever (38.5°C), irritability and painful skin. On examination he is miserable; screams when touched; has erythema of the face, axillae, neck, buttocks and groin; and peeling skin at the tip of his penis. Rubbing the skin leads to wrinkling and erosions of the epidermis. He has crusting around the mouth and nose and mild conjunctivitis. On day two of admission he develops large flaccid bullae on areas of red skin as shown in the photographs below.
Investigations on admission include:
Haemoglobin Platelets
White Cell Count Neutrophils
Serum creatinine C-Reactive Protein
136 g/L
434 x 109/L 15.9 x 109/L 10.8 x 109/L 30 μmol/L
< 3mg/L
[100-140] [150-400] [6.0-13.0] [2.0-6.0] [27-62] [<8]
Gram stain of skin: No organisms seen.
A skin biopsy from this patient would be expected to show a cleavage plane in the:
A. granular layer with a perivascular lymphocytic and neutrophilic infiltrate.
B. granular layer with no inflammatory cell infiltrate.
C. subepidermal layer with eosinophilic infiltration of the dermis.
D. subepidermal layer with full-thickness epidermal necrosis.
E. subepidermal layer with intense perivascular and interstitial mononuclear cell infiltrate.
B. granular layer with no inflammatory cell infiltrate.
2006 Part 2 Q 29
A four-year-old boy is reviewed in clinic because of a flare-up of his atopic eczema. He has not responded to his usual emollients and topical steroids.
On examination his temperature is 37°C. He is irritable, and has extensive whole-body eczema with excoriation and crusting. The lesions around his mouth are shown above.
The most appropriate treatment is:
A. aciclovir.
B. flucloxacillin.
C. more potent topical steroid.
D. mupirocin ointment.
E. pimecrolimus cream.
B. flucloxacillin.
2006 Part 2 Q33
A nine-year-old girl with systemic lupus erythematosus (SLE) presents with a painless, erythematous, blistering rash on her chest, as shown. She is afebrile. She is currently on prednisone, and has recently been given pulse cyclophosphamide.
The most appropriate initial treatment would be:
A. intravenous aciclovir.
B. intravenous flucloxacillin.
C. oral aciclovir.
D. oralflucloxacillin.
E. withhold immunosuppressants.
A. intravenous aciclovir.
2006 Paper 2 Q40
A 15-month-old infant has itchy lesions on the scalp, neck, palms and soles (as shown below). The most likely diagnosis is:
A. Coxsackie A16 infection (Hand, foot and mouth disease).
B. eczema herpeticum.
C. impetigo.
D. pompholyx (dyshidrotic eczema).
E. scabies.
E. scabies.
2006 Part 2 Q44
An eight-year-old boy presents with an isolated rash on his foot as shown above. The most appropriate initial management is:
A. oral griseofulvin.
B. oral prednisolone.
C. oral terbinafine.
D. topical mometasone.
E. topical terbinafine.
E. topical terbinafine.
2006 Paper 2 Q68
A seven-year-old girl is brought into the emergency department with a generalised rash. Her arm is shown above. This rash is most commonly found in association with:
A. administration of carbamazepine.
B. administration of cefaclor.
C. enterovirus infection.
D. herpes simplex virus (HSV) infection.
E. Mycoplasma pneumoniae infection.
D. herpes simplex virus (HSV) infection.
2006 Paper 2 Q71
A 15-year-old girl with chronic eczema presents with facial lesions as shown. The most likely infecting organism is:
A. Candida albicans.
B. Chlamydia trachomatis.
C. Herpes simplex virus.
D. Herpes zoster virus.
E. Neisseria gonorrhoeae.
C. Herpes simplex virus.
2006 Part 2 Q96
A six-month-old boy presents to the emergency department with a five day history of coryza, low grade fever and poor oral intake. He has developed an extensive migratory rash overnight and is generally miserable. On examination he has a widespread rash as shown below, with no evidence of mucous membrane involvement. He has been previously well and is not on any regular medications.
Which of the following is the most likely diagnosis?
A. Erythema marginatum.
B. Erythema multiforme.
C. Stevens-Johnson syndrome.
D. Urticaria.
E. Viral exanthem.
D. Urticaria.
What is this rash in newborn?
Erythema toxicum
2nd-3rd day of life
Trunk and limbs affected
Palms and soles spared.
Eosinophils on smear
What is this rash in neonate?
Transient Neonatal Pustular Melanosis
5% black skinned, <1% in white skinned.
Pustules surrounding erythema (cf erythema toxicum) and when ruptured, leave a collarette of scale and pigmented macule (ie melanosis) that lasts 3-4 weeks.
Palms and soles affected.
What is this neonatal rash?
Acne neonatorum
Closed comedomes on forehead, nose and cheeks typically. Occurs due to stimulation of sebacious glands from infant or maternal androgens.
Most resolve within 4 months without scarring.
Can be treated with benzoyl peroxide if not resolving.
What is this neonatal rash?
Milia
Pearly white or yellow papules from retention of keratin within dermis.
50% of newborns.
Usually forehead, cheeks, nose and chin. Can involve other areas.
Usually disappear within a month.
What is this neonatal rash?
Miliaria Crystallina
Miliaria results from sweat retention caused by partial closure of eccrine structures.
Most common on head, neck and trunk.
1-2mm vessicles without surrounding erythema.
What is this neonatal rash?
Miliaria Rubra
aka heat rash
Small erythematous papules and macules.
Caused by deeper sweat gland obstruction
Worse on covered areas (due to heat)
What is this neonatal rash?
Seborrheic Dermatitis
Cradle cap
Erythema and greasy scales
Usually scalp, can involve face, neck and ears.
Can continue for months.
