DERMATOLOGY Flashcards
Scaly papule that soon forms erythematous plaques covered with a white scale
Psoriasis
Hemorrhagic red papules that do not blanch with pressure
necrotizing vasculitis
Target-shaped lesion that consist in part of erythematous plaques
erythema multiforme
Pseudohyphae and budding yeasts is seen in
Candida infections
“Spaghetti and meatballs” yeast forms are seen in
tinea versicolor
A cytologic technique most often used in the diagnosis of herpesvirus infections (herpes simplex virus or varicella zoster virus)
Tzanck smear
An opaque to transparent, brown-pink “apple jelly” appearance on diascopy
Granulomas
Coral pink color under the wood’s lamp
Erythrasma
A superficial, intertriginous infection caused by Corynebacterium minutissimum
Erythrasma
Pale blue on wood’s lamp
Pseudomonas
Yellow fluorescence on wood’s lamp
Tinea capitis
Caused by dermatophytes (e.g. Micrisporum canis or M. audouinii)
A battery of suspected allergens is applied to the patient’s back under occlusive dressings and allowed to remain in contact with the skin for 48 h
Patch test
Patch test is used to examine evidence of
delayed hypersensitivity reactions
This is the most common type of melanoma
Superficial spreading melanoma
Such lesions usually demonstrate asymmetry, border irregularity, color variegation (black, blue, brown, pink, and white), a diameter >6 mm, and a history of change (e.g., an increase in size or development of associated symptoms such as pruritus or pain).
A flat, colored lesion, <2 cm in diameter, not raised above the surface of the surrounding skin. A “freckle,” or ephelid, is a prototype
Macule
A large (>2 cm) flat lesion with a color different from the surrounding skin
Patch
A small, solid lesion, <0.5 cm in diameter, raised above the surface of the surrounding skin and thus palpable (e.g., a closed comedone, or whitehead, in acne).
Papule
A larger (0.5 to 5.0 cm), firm lesion raised above the surface of the surrounding skin
Nodule
A solid, raised growth >5 cm in diameter.
Tumor
A large (>1 cm), flat-topped, raised lesion; edges may either be distinct (e.g., in psoriasis) or gradually blend with surrounding skin (e.g., in eczematous dermatitis).
Plaque
A small, fluid-filled lesion, <0.5 cm in diameter, raised above the plane of surrounding skin. Fluid is often visible, and the lesions are translucent
Vesicle
A vesicle filled with leukocytes
Pustules
The presence of pustules does not necessarily signify the existence of an infection
A fluid-filled, raised, often translucent lesion >0.5 cm in diameter
Bulla
A raised, erythematous, edematous papule or plaque, usually representing short-lived vasodilation and vasopermeability.
Wheal
A dilated, superficial blood vessel
Telangiectasia
A distinctive thickening of the skin that is characterized by accentuated skin-fold markings.
Lichenification
Excessive accumulation of stratum corneum
Scale
Dried exudate of body fluids that may be either yellow or red
Crust
Loss of epidermis without an associated loss of dermis.
Erosion
Loss of epidermis and at least a portion of the underlying dermis
Ulcer
Linear, angular erosions that may be covered by crust and are caused by scratching.
Excoriation
An acquired loss of substance. In the skin, this may appear as a depression with intact epidermis or as sites of shiny, delicate, wrinkled lesions
Atrophy
A change in the skin secondary to trauma or inflammation. Sites may be erythematous, hypopigmented, or hyperpigmented depending on their age or character. Sites on hair-bearing areas may be characterized by destruction of hair follicles.
Scar
Small, firm, white papules filled with keratin
Milia
Coin-shaped lesion
Nummular
Skin that displays variegated pigmentation, atrophy, and telangiectases.
Poikiloderma
A configuration of skin lesions formed from coalescing rings or incomplete rings
Polycyclic lesions
Erythema with greasy yellow-brown scale
Seborrheic dermatitis
Violaceous flat-topped papules and plaques
Lichen planus
Skin-colored or red-brown macule or papule with dry, rough, adherent scale
Actinic keratosis
Papule with pearly, telangiectatic border on sun- damaged skin
Basal cell carcinoma
Usual site of basal cell carcinoma
Face
Indurated and possibly hyperkeratotic lesions often showing ulceration and/or crusting
Squamous cell carcinoma of the skin
Usual site of squamous cell carcinoma of the skin
Face (especially lower lips, ears)
Brown plaques with adherent, greasy scale; “stuck on” appearance
Seborrheic keratosis
Symmetric erythematous papules and plaques with a collarette of scale
Pityriasis rosea
Most frequent skin reaction to drugs
Morbilliform rash – 91%
Urticaria – 6%
Populations that are at high risk for cutaneous drug reactions (4)
- Elderly
- Autoimmune disease
- Hematopoietic stem cell transplant recipient
- Acute EBV or HIV infection
CD4 count in HIV disease that have 40- to 50-fold increased risk of ADR to sulfamethoxazole and increased risk of severe hypersensitivity reactions
CD4 < 200
Drugs can trigger mediator release either by these 2 mechanism
- Direct mast cell degranulation
2. IgE-specific antibodies
NSAIDs trigger mediator release by
Direct mast cell degranulation
“anaphylactoid” reaction
Radiocontrast media trigger mediator release by
Direct mast cell degranulation
“anaphylactoid” reaction
Penicillin trigger mediator release by
IgE-specific antibodies
Caused by tissue deposition of circulating immune complexes with consumption of complement
Serum sickness
Common cause of serum sickness
Monoclonal antibodies and similar drugs
Symptoms of serum sickness usually develop how many days after drug exposure
6 or more days
Latent period – time needed to synthesize antibody
An important mechanism underlying the most common drug eruptions (morbilliform eruptions)
Delayed hypersensitivity
Genetic determinants may predispose individuals to severe drug reactions by affecting either drug metabolism or immune responses to drugs; most commonly
HLA haptotypes
Drugs that can exacerbate plaque psoriasis (6)
- NSAIDs
- Lithium
- Beta blockers
- TNF antagonists
- Interferon α
- ACE inhibitors
A drug used to treat psoriasis that May induce psoriasis (esp palmoplantar) in patients being treated for other conditions
TNF antagonists
Drugs that can worsen pustular psoriasis (2):
- Antimalarials
2. Withdrawal of systemic glucocorticoids
Follicular papular or pustular eruptions of the face and trunk resembling acne can be caused by what drug
epidermal growth factor receptor (EGFR) antagonists
Severity of the eruption correlates with a better anticancer effect
Typically responsive to and prevented by tetracycline antibiotics
Markers of drug-induced SLE (4)
- ANA
- Antihistone
- Anti-dsDNA
- p-ANCA
Drugs that may cause pemphigus (2)
- D-penicillamine
2. ACE inhibitors
Drugs that may cause bullous pemphigoid (2)
- Furosemide
2. PD-1 inhibitors
Drugs that may cause linear IgA bullous dermatosis
Vancomycin
A condition of sclerosing skin with rare internal organ involvement caused by gadolinium contrast
Nephrogenic systemic fibrosis
Mechanism of photosensitivity eruption is almost always
Phototoxicity
Blistering may occur in drug-related pseudoporphyria, particularly caused by
NSAIDs – most common
Drug that may result in severe photosensitivity, accelerated photoaging, and cutaneous carcinogenesis
Voriconazole
Drug that can cause a UV-recall reaction characterized by an erythematous, slightly scaly eruption at sites of prior severe sun exposure
Methotrexate
Blue-gray pigmentation can be caused by what 2 drugs
- long-term minocycline
2. amiodarone
Gray-brown pigmentation can be caused by what drugs (3)
- Phenothiazine
- Gold
- Bismuth
Red-brown pigmentation can be caused by what drug and what do you call this condition?
Clofazimine
Drug-induced lipofuscinosis
Hyperpigmentation of the face, mucous membranes, and pretibial and subungual areas can be caused by what drug
Antimalarials
Generalized yellow discoloration can be caused by
Quinacrine
Warfarin necrosis of the skin occurs between the how many days of therapy with warfarin
3-10 days
Common sites of warfarin necrosis of the skin (3)
- Breasts
- Thighs
- Buttocks
Usually in women
Drug induced hair loss that occurs during growth
Anagen effluvium
Occurs within days of drug administration Antimetabolite or other chemotherapeutic drugs
Drug induced hair loss that occurs during resting phase of growth
Telogen effluvium
Delay is 2-4 months following initiation of new medication
Drug-induced nail disorder characterized by transverse depression of the nail plate
Beau’s line
Drug-induced nail disorder characterized by detachment of the distal part of the nail plate
Onycholysis
Common drugs that cause onycholysis (5)
- Tetracyclines
- Fluoroquinolones
- Retinoids
- NSAIDs
- Chemotherapeutic agents
Drug-induced nail disorder characterized by detachment of the proximal part of the nail plate
Onychomadesis
Caused by temporary arrest of nail matrix mitotic activity
Common drugs that cause onychomadesis (4)
- Carbamazepine
- Lithium
- Retinoids
- Chemotherapeutic drugs
Drug-induced nail disorder characterized by inflammation of periungal skin
Paronychia
Common drugs that cause paronychia (4)
- Systemic retinoids
- Lamivudine
- Indinavir
- Anti-EGFR monoclonal antibodies
Drug reaction that is marked by dysesthesia and an erythematous, edematous eruption of the palms and soles
Acral erythema
Toxic erythema of chemotherapy
Chemotherapeutic drugs that cause acral erythema (6)
- Cytarabine
- Doxorubicin
- Methotrexate
- Hydroxyurea
- Fluorouracil
- Capecitabine
Chemotherapeutic drug that cause marked hair textural changes
Erlotinib
Chemotherapeutic drug that cause follicular eruptions and focal bullous eruptions at palmoplantar, flexural sites or areas of frictional pressure
Sorafenib
A tyrosine kinase inhibitor
Most common of all drug-induced reactions
Morbiliform eruptions
More severe reaction of morbilliform eruptions is characterized by
Nonblanching, dusky, or bright-red macules
Certain medications that carry very high rates of morbilliform eruptions (2)
- Nevirapine
2. Lamotrigine
The 2nd most frequent type of cutaneous reaction to drugs
Urticaria
Deep edema within dermal and subcutaneous tissues
Angioedema
Anaphylactoid reaction characterized by flushing, diffuse maculopapular eruption, and hypotension and what drug causes it?
Red man syndrome
Vancomycin
DRESS or DIHS has morbilliform eruptions that most frequently involve which part of the body
Face
Systemic manifestations of DRESS or DIHS (in descending order) (8)
- Lymphadenopathy
- Fever
- Leukocytosis – eosinophilia or atypical lymphocytosis
- Hepatitis
- Nephritis
- Pneumonitis
- Myositis
- Gastroenteritis
Drug that most frequently induces DIHS with renal involvement
Allopurinol
Drug that most frequently induces DIHS with cardiac and lung involvement
Minocycline
Drug that most frequently induces DIHS and wherein GI involvement is almost exclusively seen
Abacavir
Medications that typically lack eosinophilia in DIHS (3)
- Abacavir
- Dapsone
- Lamotrigine
Cutaneous reaction in DIHS usually begins ____ after the drug is started and _____ after drug cessation
2-8 weeks
persists
Reactivation of herpes virus (HHV 6 and 7, EBV, and CMV) – frequently reported in this drug related syndrome
DIHS or DRESS
Worse clinical prognosis if with reactivation
Mortality rate of DIHS / DRESS
10%
Most fatalities of DIHS / DRESS is caused by
liver failure
Management of DIHS / DRESS (6)
- Systemic glucocorticoids 1.5-2 mg/kg/d prednisone equivalent
- Mycophenolate mofetil
- Immediate withdrawal of culprit drug
- Cardiac evaluation (because of severe long-term complications of myocarditis)
- Monitor for resolution of organ dysfunction
- Monitor for development of late-onset autoimmune thyroiditis and diabetes (up to 6 months)
Drug reaction that is characterized by blisters and mucosal/epidermal detachment resulting from full-thickness epidermal necrosis in the absence of substantial dermal inflammation, and involve <10% of TBSA
SJS
Drug reaction that is characterized by blisters and mucosal/epidermal detachment resulting from full-thickness epidermal necrosis in the absence of substantial dermal inflammation, and involve 10-30% of TBSA
SJS-TEN overlap
Drug reaction that is characterized by blisters and mucosal/epidermal detachment resulting from full-thickness epidermal necrosis in the absence of substantial dermal inflammation, and involve >30% of TBSA
TEN
Painful mucosal erosions and target lesions with acral distribution and limited skin detachment and is associated with HSV
Erythema multiforme
Clinical features of SJS/TEN (4)
- Fever >390C
- Sore throat
- Conjunctivitis
- Acute onset of painful dusky, atypical, target-like lesions
Factors associated with poor prognosis in SJS / TEN (4)
- GI involvement
- Upper respiratory tract involvement
- Older age
- Greater extent of epidermal detachment
Mortality rates of SJS and TEN
10% - SJS
30% - TEN
Rare reaction pattern that is secondary to medication exposure in >90% of cases characterized by diffuse erythema or erythroderma, high-spiking fevers, innumerable pinpoint pustules most pronounced in body fold areas
Acute generalized exanthematous pustulosis
Difference between AGEP from SJS (2)
- Erosions are more superficial
2. No prominent mucosal involvement
Principal DDx for AGEP
Acute pustular psoriasis
Most commonly implicated in drug-induced vasculitis
β-lactam
Almost any drug can cause vasculitis
Most common drugs that cause drug-induced ANCA vasculitis (3)
- PTU
- Methimazole
- Hydralazine
Long-term exposure to minocycline can cause this reaction that is characterized by perivascular eosinophils on skin biopsy
Drug-induced polyarteritis nodosa
Cutaneous drug eruption that is always drug-induced
fixed drug eruptions
Most cases of drug eruptions occur during the first course of treatment with a new medication, except for
IgE-mediated urticaria and anaphylaxis
Need presentization and develop a few minutes to a few hours after rechallenge
Characteristic timing of onset following drug administration:
Morbilliform eruption
AGEP
SJS/TEN
DIHS
Morbilliform eruption – 4-14 days
AGEP – 2-4 days
SJS/TEN – 5-28 days
DIHS – 14-48 days
A key diagnostic tool for identifying the inciting drug that compile all current and past medications/supplements and the timing of administration relative to the rash
Drug chart
It is now recommended that 1st degree family members of patients with severe cutaneous reactions also should avoid causative agents. This recommendation is most relevant for what drugs (2)
sulfonamides and antiepileptic medications
Type of ADR that is IgE-mediated
Type I
Type of ADR that is IgG-mediated
Type II
Type of ADR that is secondary to immune complex
Type III
Type of ADR that is T lymphocyte– mediated macrophage inflammation
Type IVa
Type of ADR that is T lymphocyte– mediated eosinophil inflammation
Type IVb
Type of ADR that is T lymphocyte– mediated cytotoxic T lymphocyte inflammation
Type IVc
Type of ADR that is T lymphocyte– mediated neutrophil inflammation
Type IVd
Urticaria is what type of ADR?
Type I
Angioedema is what type of ADR?
Type I
Anaphylaxis is what type of ADR?
Type I
Drug-induced hemolysis is what type of ADR?
Type II
Thrombocytopenia is what type of ADR?
Type II
Vasculitis is what type of ADR?
Type III
Serum sickness is what type of ADR?
Type III
Drug-induced lupus is what type of ADR?
Type III
Tuberculin test is what type of ADR?
Type IVa
Contact dermatitis is what type of ADR?
Type IVa
DIHS is what type of ADR?
Type IVb
SJS/TEN is what type of ADR?
Type IVc
AGEP is what type of ADR?
Type IVd
Morbiliform eruptions is what type of ADR?
Type IVb and IVc
Most common culprit drugs for SJS/TEN? (4)
- Sulfonamides
- Anticonvulsants
- Allopurinol
- NSAIDs
Most common culprit drugs for DIHS/DRESS? (4)
- Anticonvulsants
- Sulfonamides
- Allopurinol
- Minocycline
Most common culprit drugs for AGEP? (3)
- β-Lactam antibiotics
- Calcium channel blockers
- Μacrolide antibiotics
Most common culprit drugs for serum sickness? (3)
- Antithymocyte globulin
- Cephalosporins
- Monoclonal antibodies
Most common culprit drugs for angioedema? (3)
- ACE inhibitors
- NSAIDs
- Contrast dye