RAMB - Agosto 2016

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2016; 62(5):468-473

possible causative agents. Carcinomas and lymphomas are

also associated. Notwithstanding the different known eti-

ologies, SJS is idiopathic in 25 to 50% of cases.

1,7

linical

picture

For most drugs triggering these reactions, there is an inter-

val ranging from4 to 28 days between the beginning of drug

use and the onset of signs and symptoms. The highest risk

of developing SJS and TEN occurs in the first 2 months of

treatment with risk drugs on a continuous basis.

Both diseases can start with prodromal symptoms

lasting up to 1 week, such as fever, sore throat, coughing,

eye burning, myalgia and arthralgia. After this period

there may be a discrete maculopapular rash, similar to a

morbilliform rash.

1,4

There may be atypical target lesions (with two instead

of the three characteristic concentric rings found in EM)

on the back of the hands, palms, sole of the foot, exten-

sor surface of the limbs, neck, face, ears and perineum,

with prominent involvement of trunk and face.

1,4

The rash begins on the trunk with subsequent gener-

alization, usually sparing the palmoplantar areas. Macu-

lar lesions become purplish, and epidermal detachment

occurs, resulting in flaccid blisters that converge and break,

resulting in extensive sloughing of necrotic skin (Figure 1).

Nikolsky’s sign is positive in perilesional skin.

The difference between SJS and TEN would be the

percentage of affected body area: cases involving less than

10% of the body would be classified as SJS, and those with

over 30% of involvement would be TEN. Cases with in-

volvement between 10 and 30% would be considered a su-

perposition of the two entities.

Mucosal involvement occurs in two or more distinct

mucosal surfaces and may precede or follow the skin in-

volvement. It begins with enanthem and edema that cause

erosions and pseudomembranous formations in the eyes,

mouth, genitals, throat and upper airways. About 10-30%

of cases occur with fever and lesions in the gastrointesti-

nal and respiratory tracts.

Ocular involvement may be present in 39 to 61% of

the cases presenting complications such as corneal ulcer,

anterior uveitis, and panophthalmitis. Gastrointestinal

adhesions, urinary incontinence, vaginal stenosis, renal

tubular necrosis, renal failure, skin ulcerations with re-

infection and non-esthetic scars are not uncommon.

Loss of integrity of the skin barrier leads to increased

chance of secondary bacterial infection, as well as distur-

bances in electrolyte balance and thermoregulation.

aboratory

testing

There are no laboratory tests to point out the drug caus-

ing the disorder and, therefore, diagnosis is clinical.

FIGURE 1

Patient with Stevens-Johnson syndrome, 5 days after

the use of piroxicam. Courtesy: Dr. Karine Simone, Internal

Medicine outpatient clinic, Dermatology, Santa Casa de São Paulo.