Hemangioma
Clinical Findings
A red, rubbery vascular plaque or nodule with a characteristic growth pattern
is a hemangioma. The lesion is often not present at birth but is represented
by a permanent blanched area on the skin that is supplanted at age 2–4
weeks by red papules. Hemangiomas then undergo a rapid growth or
“proliferative” phase, where growth of the lesion is out of proportion to
growth of the child. At 9–12 months, growth stabilizes, and the lesion slowly
involutes over the next several years. Histologically, hemangiomas are
benign tumors of capillary endothelial cells. They may be superficial, deep,
or mixed. The terms strawberry and cavernous are misleading and should
not be used. The biologic behavior of a hemangioma is the same despite its
location. Fifty percent reach maximal regression by age 5 years, 70% by age
7 years, and 90% by age 9 years, leaving redundant skin, hypopigmentation,
and telangiectasia. Local complications include superficial ulceration and
secondary pyoderma. Rare complications include obstruction of vital
structures such as the orbit or airway.
Treatment
Complications that require immediate treatment are (1) visual obstruction
(with resulting amblyopia), (2) airway obstruction (hemangiomas of the
head and neck [“beard hemangiomas”] may be associated with subglottic
hemangiomas), and (3) cardiac decompensation (high-output failure).
Historically, the preferred treatment for complicated hemangiomas has
been prednisolone, 2–3 mg/kg orally daily for 6–12 weeks. Currently, oral
propranolol (2 mg/kg/d divided bid) has replaced systemic steroids as the
treatment of choice at most institutions. Reported side effects are sleep
disturbance, hypoglycemia, and bradycardia. Recommendations on
pretreatment cardiac evaluation vary between institutions. Topical β-
adrenergic receptor antagonist timolol, administered as a gel-forming
solution (GFS), has also been used for problematic lesions on the lip or
eyelid, with variable results. Interferon α2a has also been used to treat serious
hemangiomas. However, 10% of patients with hemangiomas treated with
interferon α2a have developed spastic diplegia, and its use is very limited. If
the lesion is ulcerated or bleeding, pulsed dye laser treatment is indicated to
, NR 602 WEEK 2 QUIZ
initiate ulcer healing and immediately control pain. The Kasabach-Merritt
syndrome, characterized by platelet trapping with consumption
coagulopathy, does not occur with solitary cutaneous hemangiomas. It is
seen only with internal hemangiomas or the rare vascular tumors such as
kaposiform hemangioendotheliomas and tufted angiomas.
Ticks
Rickettsiae are pleomorphic, gram-negative coccobacilli that are obligate
intracellular parasites. Rickettsial diseases are often included in the
differential diagnosis of febrile rashes. Severe headache, myalgia, and
pulmonary symptoms are prominent manifestations of rickettsial disease.
The endothelium is the primary target tissue, and the ensuing vasculitis is
responsible for severe illness.
All rickettsioses are transmitted by arthropod contact (ticks, fleas, lice—
depending on the disease), either by bite or by contamination of skin breaks
with vector feces. Except Rocky Mountain spotted fever and murine typhus,
all other rickettsial diseases have a characteristic eschar at the bite site,
called the tache noire. Evidence of arthropod contact by history or physical
examination may be lacking, especially in young children. The geographic
distribution of the vector is often the primary determinant for suspicion of
these infections. Therapy often must be empiric. Many new broad-spectrum
antimicrobials are inactive against these cell wall–deficient organisms;
tetracycline is usually effective.
Q fever, which is not a rickettsiae, is included here because it was long
classified as such and, like rickettsiae, is an obligate intracellular bacterium.
It is not transmitted by an insect vector and is not characterized by rash.
HUMAN EHRLICHIOSIS
ESSENTIALS OF DIAGNOSIS & TYPICAL FEATURES
• Residing or travel in endemic area when ticks are active.
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