Page 177 - Concise Pathology for Exam Preparation ( PDFDrive )

162 SECTION I General Pathology

Erythematous,
scaly plaque

Thickened greater
auricular nerve
FIGURE 7.3. Large, well-defined, hy-
popigmented plaque of paucibacillary
leprosy showing irregular borders.

ENL nodule
with central
necrosis

FIGURE 7.4. Multiple, large, variable-sized plaques of
lepromatous leprosy.

TABLE 7.3. Differences between tuberculoid and lepromatous leprosy
Features Tuberculoid leprosy Lepromatous leprosy

T-cell-mediated Well developed Absent/very weak
immunity
Lepromin test Strongly positive Negative
Skin lesions Asymmetrical, single or few, well- Symmetrical multiple, ill-defined, hypopigmented
defined, hypopigmented patches/ or erythematous, maculopapular or nodular
plaques or erythematous macular lesions; sensory loss late and less prominent
lesions; all with sensory loss
Histology Well-formed epithelioid cell granulo- Foamy macrophages/lepra cells in dermis sepa-
mas eroding basal layer of epidermis, rated from epidermis by a clear grenz zone.
no clear grenz zone. Paucibacillary Multibacillary
CD41 T-cells Present in abundance at periphery of Almost absent
granuloma
CD81 T-cells Very few; at centre of lesion Present (more in number) in a diffuse manner
Infectivity Low High
Involvement Mostly nerve (severely affected, may be Skin, peripheral nerves, anterior eye, upper air-
destroyed), skin ways, testes, feet, hands
Complications Related to nerve damage like paralysis, Type II immune complex-mediated reaction or ery-
distinct sensory disturbances thema nodosum leprosum (ENL) causing vascu-
litis, glomerulonephritis, nerve-related damage
Prognosis Milder disease; better prognosis Extensive, progressive disease; bad prognosis

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