Dermatology Flashcards
Rosacea
Papules, pustules and telangiectasia on an erythematous background
Cheeks, forehead and chin
Erysipelas
Indurated skin infection with a well-defined raised edge
Painful
Erythematous
Seborrhoeic dermatitis
Red and scaly rash involving
Eyebrows
Eyelids
Nasolabial folds
Chloasma / Melasma
Increased browning pigmentation, usually confined to symmetrical areas of the cheeks.
Common in pregnancy
Can be caused by drugs:
*COCP
*Hydroxychloroquine
*Diphenylhydrazine
Malar flush
Mitral stenosis
Pulmonary stenosis
Rosacea
SLE
Mesenteric adenitis
Spider naevi
Pregnancy
Liver disease
Vitamin B deficiency in normal people
Erysipelas vs cellulitis
Erysipelas usually involves the superficial subcutaneous tissue, as a result the skin is hard, red and shiny. It’s usually caused by group A
Cellulitis usually involves the deep tissue resulting in tenderness and swelling. Usually caused by group or Streptococcus pyogenes.
Merkel-cell carcinoma definition
aggressive cutaneous
neuroendocrine tumour that is associated with polyomavirus infection,
immunosuppression, advanced age, and sun exposure
Features of Merkel-cell carcinoma
Asymptomatic or non-tender
Expanding rapidly
Immune suppressed
Older than 50
UV-exposed fair skin
Pyogenic granuloma
Appears as a painless red, brownish-red or blue-black spot. It grows rapidly over a period of a few days to weeks to a final size of 1–2
cm (rarely up to 5 cm). It typically bleeds easily and may ulcerate to form a crusted
sore
Melanoma excision protocol
For melanoma in situ, a 5 mm clear margin is desirable.
For melanoma less than 1 mm thickness , a 1 cm clear margin is desirable.
For melanomas 2-4 mm thickness, a 1-2 cm clear margin is desirable.
For melanomas more than 4 mm thickness, a clear margin of 2 cm is required.
highest risk for developing malignant melanoma
Multiple dysplastic nevus
highest risk of developing squamous cell carcinoma
-Age over 40
-History of non-melanoma skin cancers
-Tendency to burn rather than tan when exposed to the sun
Fair complexion is a risk factor for developing squamous cell carcinoma of the skin however it is not useful in assessing the severity of the risk factors contributing to
the disease
Urticaria (hives) characterized by
pruritic, oedematous papules, and plaques that vary in size and come and go, often within hours. Folliculitis caused
by Pseudomonas aeruginosa can cause a rash, often after exposure to hot tubs
Treatment of urticaria
Oral promethazine
Yellow-colored cutaneous plaques as well as yellow bumps on his elbows and buttocks
Eruptive xanthoma
Xanthomatous skin lesions can be important cutaneous clues for underlying lipid disorders
Treatments varicella zoster virus
antiviral (within days)
TCA
varicella zoster virus
also known as Shingles
characterized by a painful, unilateral vesicular eruption in a dermatomal distribution. The clinical manifestations of uncomplicated herpes zoster typically include a dermatomal vesicular rash, and acute neuritis, which precedes or occurs simultaneously with the rash.
Secondary pellagra due to vitamin B3 deficiency
Due to not enough absorption due to metabolism problems
– Anorexia nervosa.
– Chronic diarrhoea.
– Chronic alcoholism.
– Hartnup disease.
– Carcinoid syndrome
– Colitis.
– Hepatic cirrhosis
Primary Pellagra
caused by dietary deficiency of tryptophan or niacin (vit B3)
The classic triad of dermatitis, diarrhoea and dementia is not always present
Tinea capitis
Almost exclusively seen in children, main differentiator to alopecia areata
-Black dot ringworm: hairs break off at base leaving “black dots” in hairless patches.
-Grey patch ringworm: circular, scaly, hairless patches develop.
-Seborrheic form: diffuse scale with minimal to no hair loss
Squamous cell carcinoma pre-cursor disease
typical actinic keratoses (AK).
Over ten years, there is 6% chance that AK progresses to squamous cell carcinoma.
Most common skin cancers hierarchy
Basal cell carcinoma (BCC) is the most common skin cancer, accounting for about
68% of all skin cancers. Squamous cell carcinoma (SCC) accounts for 28%, melanoma 3%
Lichen sclerosus
inflammatory condition of the skin.
Bimodal peak: prepubertal
girls, perimenopause.
Pruritus is the main symptom.
Main differential diagnosis is atrophic vaginitis.
First-line treatment includes steroids.
Lifelong surveillance with 6-monthly check-up is required due to the risk of squamous cell carcinoma of the skin
Pemphigus vulgaris vs Bullous pemphigoid
PV: flaccid bullae and mucosal erosions
Diagnosis of Lichen Planus
commonly occurs as pruritic, purple/pink, polygonal
papules and plaques on the skin of the extremities and trunk (cutaneous LP), but
lesions may also appear on the genitalia (genital LP) (genital LP) or oral mucosa (oral LP). The
lesions often have white, lacy markings known as Wickham striae and can form along the lines of minor trauma
Treatment includes topical high-potency glucocorticoids topical high-potency glucocorticoids (eg, betamethasone). The disorder is self-limited and typically resolves within 2 years.
difference between lipoma and epidermoid cyst
characteristic physical feature of a lipoma is the lobulated contour
skin malignancies is most likely to arise from a burn scar
Squamous cell carcinoma
Amiodarone + Warfarin
Haematoma
Coeliac disease causes what rash
dermatitis herpetiform
Diagnosis of Ramsay hunt syndrome
Cause of Ramsay Hunt Syndrome
Treatment of acne
1st line: isotretinoin
2nd line: Doxycycline
Most commonly affected nail site on Tinea Unguium
Nail Plate
Pattern of lentigo melanoma
slow growing (3 years)
