Dermatology Flashcards
Give some causes of pyoderma gangrenosum?
Inflammatory bowel disease Acute leukaemia Polycythemia rubra vera Autoimmune hepatitis Wegeners granulomatosis Myeloma
For how long should children with impetigo stay off school for?
Stay off until had 48h of effective treatment
What is necrobiosis lipoidica?
Shiny area on shin with yellowish skin and telangiectasia seen in diabetes mellitus
What does pyoderma gangrenosum look like?
Recurring nodulo pustular ulcers with tender red/blue overhanging necrotic edge, healing with cribriform scars
What is the difference between bullous pemphigoid and pemphigus vulgaris?
Bullous pemphigoid: tense bullae filled with clear fluid on normal or erythematous skin. Blistering occurs subepidermally
Pemphigus vulgaris: thin walled and fragile blisters, few intact blisters occurring at dermal epidermal junction
What is Kawasaki disease?
Mucocutaneous lymph node syndrome
Fleeting erythematous rash associated with fever, cracked lips, red tongue, swollen hands and swollen neck glands
What is necrobiosis lipoidica diabeticorum?
Painless rash with central lipid like core surrounded by brownish purplish periphery
Found in type 1 and 2 diabetes
How do you treat necrobiosis lipoidica diabeticorum?
PUVA and improved therapeutic control
What is Kawasaki disease? How does it present?
Acute vasculitis of medium sized vessels classically involves the coronary arteries
Prolonged fever for more than 5 days with mucocutaneous changes and lymphadenopathy
Desquamation of fingers and toes begins in periungual region, may involves palms and soles and is observed 1-2 weeks after fever
How does measles present?
Generalised macular rash starting on head and spreads to trunk and extremities over few days
Rash lasts at least 3 days and fades in order of appearance
Can leave behind a brownish discolouration and can become confluent over the buttocks
A 26 year old man presents with weight loss, generalised pruritus particularly over his bottom. On examination there are some vesicles and urticarial papules over his bottom. What is it?
Dermatitis herpetiformis - systemic manifestation of coeliac
A 30 year old female who is 28 weeks pregnant presents with hyperpigmentation around cheeks, eyes and forehead giving a mask like appearance. What is it?
Melasma - mask of pregnancy
With what infections is erythema nodosum associated?
TB, sarcoid and mycoplasma
A 64 year old male presents with multiple discrete lesions of approximately 0.5-1cm in diameter over his scalp, neck and back of hands. They are scaly and rough surfaced. What are they?
Actinic keratosis
A 40 year old man presents with pruritic flat topped papules around his wrist. He has a history of bipolar disorder and takes lithium. On examination there are widespread white lace like streaky lesions on the papules and on the buccal mucosa. What is it?
Lichen planus
What drugs can cause lichen planus?
Lithium Gold Quinine Beta blockers Spironolactone
What is the correct name given to white lace like patterns found in lichen planus?
Wickhams striae
A 3 year old girl presents with macular confluent rash which appeared initially behind the ears and has spread. Over past 5 days she has had low grade fever, catarrh and conjunctivitis. Her mother is vague about her imms hx. What does she have?
Measles
What type of organism causes measles?
RNA paramyxovirus
How is measles spread?
Respiratory droplets
What is the incubation period for measles?
10-21 days
What symptoms occur in the prodromal phase of measles?
Fever Conjunctivitis Runny nose Coughing Last 5 days
What are koplik spots?
Bright red lesions with central white dot which appear on buccal mucosa in measles
How is a diagnosis of measles made?
Clinical features
Viral culture from lesions
Greater than 4x rise in antibody titres
What is subacute sclerosing panencephalitis?
Progressive brain disorder related to measles
Abnormal immune response leading to brain inflammation several years after measles infection
What are some complications of measles?
Otitis media
Pneumonia
Meningitis
Subacute sclerosing panencephalitis
A 2 year old boy is mildly unwell. His mother noticed vesicles in his mouth, palms and soles of his feet. What does he have and what is the causative organism?
Hand foot and mouth
Coxsackie A16 virus
What are characteristic features of hand foot and mouth disease?
Fever
Sore throat
Ulcerating vesicles in palms, oropharynx and soles
What is the incubation period for hand foot and mouth?
5-7 days
How do hand foot and mouth lesions heal?
Without crusting
How is chicken pox spread?
Respiratory droplets and contact with somebody who has shingles
What is the causative organism in chickenpox?
Varicella zoster virus
What are some complications of chickenpox?
Pneumonia
Encephalitis
Bacterial infection of skin
What is the incubation period for chickenpox?
14-21 days
What symptoms might be experienced in the prodromal phase of chickenpox?
Malaise
What are the 3 stages of a chickenpox rash?
Spots: red raised spots on face or chest before spreading to rest of body
Blisters: over next few hours or following day, very itchy fluid filled blisters develop on top of the spots
Scabs and crusts: after a further few days, blisters dry out and scab over to form crust which gradually fall off by themselves over next week or 2
When is chickenpox contagious until?
Until all blisters have scabbed over
Usually 5 or 6 days after rash appears
In which patients with chickenpox might you use antiviral therapy?
Systemic disease in immunocompromised
What is the first and second line treatment for scabies?
Permethrin
Malathion
What is alopecia areata?
Autoimmune condition causing discrete areas of hair loss
What is treatment for alopecia areata?
Cortisone injections into affected area
Topical cortisone creams
What are cavernous haemangiomas?
Well circumscribed and lobulated lesions which appear in first 2 weeks of life on face neck or trunk
Blood vessel malformation - benign tumour
What are symptoms of varicella pneumonia?
Tachypnoea Cough Dyspnoea Fever Cyanosis Pleuritic chest pain Haemoptysis
What are naevus flammeus?
Capillary malformation
Usually present at birth
Mainly in region supplied by cranial nerve 5
Port wine stain
If you have a well child with a cough and cold with small petechiae in the distribution of the SVC (right arm, head, neck and trunk above diaphragm). What do they have?
Cough petechiae
Vigorous coughing/vomiting raise SVC pressure sufficiently to cause capillary bleeding
What is onychogryphosis?
Over proliferation of the germinal matrix leading to excessive growth of the nail plate
How do you treat onychogryphosis?
Zadeks procedure - avulsion of nail and ablation of nail bed
Where do you find pyogenic granulomas?
Hands and face of children and young adults
Lips and gums of pregnant women
What is a pyogenic granuloma?
Benign capillary haemangiomas
How do you treat a pyogenic granuloma?
Curettage and diathermy of the base
What two features of an excised melanoma can give prognostic information about the chance of cure?
Breslow thickness
Clark level
What are predisposing factors for squamous cell carcinoma (SCC)?
Sun exposure
Radiation exposure
Pre malignant conditions: bowens, senile keratosis, lupus vulgaris, Paget’s disease
Inherited: xeroderma pigmentosum, albinism
Chronic irritation: marjolins ulcer, leukoplakia, varicose veins, osteomyelitis sinus
Infection: HPV 5 and 8
What is the histopathologic pattern in papular urticaria?
Mild subepidermal oedema
Extravasation of erythrocytes
Interstitial eosinophils
Exocytosis of lymphocytes
What bug causes scarlet fever?
Streptococcal group A infection
What bug causes cellulitis?
Streptococcus pyogenes
Sometimes staph aureus
What are multiple or genital molluscum associated with?
HIV infection
How is molluscum contagiosum transmitted?
Direct skin to skin contact
What causes hidradenitis suppurativa?
Occlusion of the ducts of apocrine glands by antigen antibody complexes leading to secondary infection and abscess formation
Which bug causes cutaneous anthrax?
Bacillus anthracis
What are risk factors for cutaneous anthrax?
Contact with infected hoofed animals - sheep goats
What is the treatment for cutaneous anthrax?
Ciprofloxacin
Doxycycline
Penicillin