riasis manifests, it is important to receive prompt
and appropriate medical treatment as well as iden-
tify and avoid triggers. Limited sun exposure, with
precautions to prevent SUNBURN, may mitigate
attacks and help the skin remain healthy.
See also BLOOD DONATION; BULLOUS PEMPHIGOID;
JOINT; KERATINOCYTE; LESION; NAILS; PEMPHIGUS; STRESS
AND STRESS MANAGEMENT.
purpura Smooth, moderately sized lesions, typi-
cally dark red to reddish purple, that result from
bleeding under the surface of the SKIN. Purpura
often look like small bruises and may occur any-
where on the body, including mucous mem-
branes. The presence of purpura signals an
underlying health condition resulting either from
PLATELETdeficiency, which delays COAGULATION(the
clotting process), or bleeding due to systemic
INFLAMMATION or INFECTION. As some of these
underlying conditions are serious and potentially
life-threatening, the appearance of purpura
(except senile purpura and actinic purpura, which
are common in aging skin) requires immediate
medical evaluation. The doctor can distinguish
purpura from other discolorations by applying
gentle pressure to them. Purpura remain discol-
ored, while other kinds of lesions often blanch
(turn lighter).
CONDITIONS ASSOCIATED WITH PURPURA
adverse DRUGreaction aging
ANAPHYLAXIS congenital
congenitalRUBELLAsyndrome CYTOMEGALOVIRUS(CMV)
immune thrombocytopenic meningococcal
purpura (ITP) SEPTICEMIA
ROCKYMOUNTAIN SPOTTED thrombotic thrombocytopenic
FEVER purpura (TTP)
VASCULITISSee also ECCHYMOSIS; LESION; PETECHIAE.pustule A blisterlike formation that contains a
pus, thick fluid of white blood cells, cellular
debris, and sometimes BACTERIA. Pustules tend to
hurt and sometimes itch. They commonly develop
in numerous dermatologic conditions ranging
from ACNEto FOLLICULITISto PSORIASIS. Often pus-
tules resolve without medical intervention, going
away when the underlying condition causing
them is under control. Warm, moist compresses or
soaking and sometimes medications to reduce
INFLAMMATIONor fightINFECTIONcan speed HEALING.
Topical or oral ANTIBIOTIC MEDICATIONSmay be nec-
essary when there is infection.
See alsoMACULE; NODULE; PAPULE.PUVA therapy See PHOTOTHERAPY.190 The Integumentary System
TREATMENTS FOR PSORIASISTopical Medications
alclomestasone amcinonide anthralin
betamethasone calcipotriene clobetasol
coal tar desonide desoximetasone
diflorasone flumethasone fluocinonide
flurandrenolide halcinonide halobetasol
hydrocortisone methlprednisolone mometasone
prednisolone salicylic acid triamconolone
Phototherapy
PUVA phototherapy excimer laser ultraviolet B (UVB) phototherapy
Systemic Medications
acitretin alefacept cyclosporine
efalizumab etanercept hydroxyurea
infliximab methotrexate mycophenolate mofetil
6-thioguanine sulfasalazine tretinoin