CHAPTER 7: ERYTHEMA AND URTICARIA Flashcards
Is usually
most marked on the hypothenar areas and is associated with
an elevated level of circulating estrogen. Cirrhosis, hepatic
metastases, and pregnancy are common causes.
Erythema palmare
Erythema multiforme major is most often caused by
Mycoplasma infection
Erythema multiforme minor is usually caused by
HSV infection
Recurrent self limited disease Sharply marginated, erythematous macules then evolve to papules Target lesions observed in palms and soles Koebner phenomenon
EM minor
Type of EM: Frequently accompanied by a febrile prodrome Lesions on extremities and face, may include trunk Mucous membrane disease prominent
EM major
Describe the classic “target” or “iris” lesion of erythema multiforme
This lesion is the classic “target” or “iris”
lesion with three zones:
central dusky purpura;
an elevated,
edematous, pale ring; and surrounding macular erythema
(Figs. 7-2 and 7-3)
What diagnostic test is necessary to exclude paraneoplastic pemphigus from mycoplasma-induced EM major?
Direct immunoflorescence
is the most common
gyrate erythema.
. . .
It is characterized by asymptomatic annular
or polycyclic lesions that grow slowly (2–3 mm/day), rarely
reaching more than 10 cm in diameter. Characteristically,
there is a trailing scale at the inner border of the annular
erythema (Fig. 7-7). The surface is typically devoid of crusts
or vesicles, although atypical cases with telangiectasia and
purpura have been described. Lesions usually occur on the
trunk and proximal extremities. Mucosal lesions are absent
Erythema annulare centrifugum
Histologically, the epidermis will show mild focal spongiosis and parakeratosis. Within the superficial dermis and at
times the deep dermis, lymphocytes are organized tightly
around the blood vessels in a pattern described as a “coat
sleeve” arrangement
Erythema annulare centrifugum
a rare disease that is striking and unique in appearance. Lesions consist of undulating
wavy bands of slightly elevated erythema with trailing scale
over the entire body. Lesions migrate rapidly (up to 1 cm/day)
and are characteristically concentric, giving the skin a “wood
grain” appearance (Fig. 7-8)
Erythema gyratum repens
Sharply marginated rapidly extending, tender, erythematous or violaceous, painful, elevated plaque, 2-10cm diameter Face, neck, upper trunk and extremities May burn but do not itch Fever
Sweet syndrome Acute febrile neutrophilic dermatosis
Majority of cases of Sweet syndrome follow this infection
URTI
Pregnancy associated Sweet syndrome usually presents in what trimester
1st or 2nd
Treatment for Sweet syndrome
Self limited Oral prednisone 1mg/kg/day
Begins as an inflammatory pustule with a surrounding halo that enlarges and begins to ulcerate Lower extremities and trunk
Pyoderma gangrenosum
Least aggressive form of pyoderma gangrenosum
Vegetative
Disease most often associated with pyoderma gangrenosum
IBD
Most common inherited auto inflammatory syndrome
Familial Mediterranean fever
Autosomal recessive Recurrent 12-72h of fever and monoarthritis and erysipela like erythema
Familial Mediterranean fever
Treatment for familial Mediterranean fever
Colchicine
Revised diagnostic criteria for diagnosis of Sweet
syndrome*
Major criteria
- Abrupt onset of erythematous plaques or nodules,
occasionally with vesicles, pustules, or bullae - Nodular and diffuse neutrophilic infiltration in the dermis with
karyorrhexis and massive papillary dermal edema
Minor criteria
- Preceded by a respiratory infection, gastrointestinal tract
infection or vaccination, or associated with:
* Inflammatory disease or infection
* Myeloproliferative disorders or other malignancy
* Pregnancy - Malaise and fever (>38°C [100.4°F])
- Abnormal laboratory findings ≥3 of the following:
* Erythrocyte sedimentation rate >20 mm/hr
* C-reactive protein elevated
* Leukocytosis >8000/mm3
* Left shift with >70% neutrophils - Excellent response to treatment with systemic corticosteroids
*Both major criteria and two minor criteria are needed for diagnosis
Vascular reaction of the skin characterized by appearance of wheals surrounded by red halo or flare with severe itching Caused by localized edema
Urticaria
Acute and chronic urticaria timeline
Acute: 12 hrs to 6 wks
Chronic: more than 6 wks
Sharply localized edema or wheal with a surrounding erythematous flare after the skin has been stroked 2-5% of population
Dermatographism
Cholinergic urticaria is produced by the action of acetylcholine on what cell
Mast cells
Adrenergic urticaria is mediated by this hormone
Norepinephrine
Management of cholinergic and adrenergic urticaria
- H2- antihistamine
- Monteleukast
- Propanolol
- Danazol
Angioedema in the absence of urticaria can be due to
hereditary angioedema or an ACE inhibitor.
. . .
C1 esterase deficiency does not cause hives, only angioedema, and measurement of C4 is indicated. If C4 is low, an evaluation of C1
esterase inhibitor is appropriate
Intense flushing may be associated with
Rosacea
. . .
In patients with rosacea, exercise, ambient heat or
cold, spicy foods, alcohol, and hot beverages are common
triggers for flushing.
drugs associated with flushing include
niacin, calcium channel blockers, cyclosporine, chemotherapeutic agents, vancomycin, bromocriptine, intravenous contrast material, sildenafil and related drugs for erectile
dysfunction, and high-dose methylprednisolon
Define erythema
means blanchable redness (hyperemia) of
the skin. A number of reactive skin conditions are referred
to as erythema. These include toxic erythemas related to
viral and bacterial infections, erythema multiforme, erythema
nodosum, and the gyrate (figurate) erythemas
As treatment and prognosis are related in part to the inciting agent, it is useful to classify erythema multiforme (EM) as follows:
Herpes simplex–associated EM (HAEM)
* Erythema multiforme major (most often caused by
Mycoplasma)
* Chronic oral EM
* Contact dermatitis–induced EM (see Chapter 6)
* Radiation-induced EM (see Chapter 6)
* Idiopathic
is a recurrent selflimited disease, usually of young adults, occurring seasonally
in the spring and fall, with each episode lasting 1–4 weeks. The
individual clinical lesions begin as sharply marginated, erythematous macules, which become raised, edematous papules
over 24–48 h. The lesions may reach several centimeters in
diameter. Typically, a ring of erythema forms around the
periphery, and centrally the lesions become flatter, more purpuric, and dusky. This lesion is the classic “target” or “iris”
lesion with three zones: central dusky purpura; an elevated,
edematous, pale ring; and surrounding macular erythema
(Figs. 7-2 and 7-3)
Herpes simplex–associated EM (HAEM) (erythema multiforme minor)
How is SJS distinguised from EM?
Erythema multiforme major is frequently accompanied by a
febrile prodrome and sometimes arthralgias. It occurs in all
ages, is centered on the extremities and face, but more often
than EM minor may include truncal lesions, which are papular
and erythematous to dusky in color. Mucous membrane
disease is prominent and often involves not only the oral
mucosa and lips, but the genital and ocular mucosa as well
(Fig. 7-5).
SJS is distinguished morphologically by the presence
of purpura or bullae in macular lesions of the trunk (Fig. 7-6).
