The diagnosis of Stevens–Johnson syndrome and TEN is made by skin biopsy. Sections of
frozen skin will demonstrate full-thickness epidermal necrosis. Because extensive skin
detachment results in massive transepidermal fluid losses, patients with these maladies are
managed similarly to patients who have had extensive burn injuries. Sepsis can result
secondary to microbial colonization of denuded skin. Mortality rates are 5% for Stevens–
Johnson syndrome and 50% for TEN (70).
Secondary Syphilis
Syphilis is a systemic disease caused byTreponema pallidum. It is classified into primary,
secondary, early latent, late latent, and tertiary stages. The lesion of primary syphilis, the
chancre, usually develops about 21 days after infection and resolves in one to two months.
Patients with secondary syphilis can present with rash, mucosal lesions, lymphadenopathy,
and fever. The rash of secondary syphilis may be maculo-papular, papulosquamous, or
pustular and is characteristically found on the palms and the soles (Fig. 6).
The diagnosis of syphilis is based on nontreponemal tests [e.g., Venereal Disease
Research Laboratory (VDRL), Rapid Plasma Reagin (RPR)] and specific treponemal tests [e.g.,
Fluorescent Treponemal Antibody Absorbed (FTA-ABS) andT. pallidumparticle agglutination
(TP-PA)]. The nontreponemal tests are used to screen for disease and follow up treatment. The
specific treponemal tests are used to rule in the diagnosis of syphilis because false-positive
nontreponemal tests can occur. Darkfield examination of skin or mucous membrane lesions
can be done to diagnose syphilis definitively during the early stages as well.
West Nile Virus
West Nile virus (WNV) is transmitted to humans from the bite of an infected mosquito (75). The
virus normally circulates between mosquitoes and birds. The first reported outbreak in the
United States was in New York in 1999, and since then WNV has spread southward and
westward (76–79). WNV has become seasonally endemic, with peak activity for transmission
from July to October in temperate zones and from April to December in warmer climates (77,79).
Figure 6 Papulosquamous rash
on wrist and hands of patient with
secondary syphilis.Source: Cour-
tesy of the CDC/Susan Lindsley,
Public Health Image Library.32 Engel et al.