such scenarios occur in springbok, but they would be
considered likely.
Following innoculation of the virus there is a viremic
phase with skin nodules usually developing around
28 days later. Skin nodules usually appear within 48
hours of the febrile reaction.
Clinical Signs and Pathology
Cutaneous nodules, lymphadenopathy and pyrexia are
the lesions most commonly described in springbok.
The cutaneous lesions are firm, circumscribed,
nodules ± 0.5-5.0 cm in diameter with lesion
distribution being similar to that described in cattle
namely head, neck, limbs, other, genitalia and
perineum (figure 1 and figure 2). Nodules affecting the
scrotum, perineum, udder, vulva, glans penis, eyelids,
and conjunctiva are usually flatter (figure 2 arrow).
Typically, nodules undergo necrosis and sequestration,
but some may resolve rapidly and completely, while
a few may become indurated and persist as hard
intradermal lumps for many months. There is a high
risk of secondary bacterial infection during the period
of necrosis and sequestration.
Figure 2: Springbok – Lumpy skin disease demonstrating
nodules on the eyelids have a faller appearance
(arrow). (Courtesy Dr Martin Malan)
Diagnosis
Collection of skin biopsies into 10% buffered
formalin for histopathology and subsequent
immunohistochemistry forms the basis of disease
diagnosis. Immunohistochemistry (IHC) for LSDV is
a rapid, specific and sensitive procedure for disease
diagnosis, as it enables demonstration of the virus
within the histological lesions allowing for confident
confirmation of clinically disease. Polymerase chain
reaction (PCR) has largely replaced virus isolation as
a diagnostic procedure for detection of the virus. The
preferred samples for PCR analysis include fresh skin
nodules, scabs or dried swabs thereof, as these tissues
carry high concentrations of virus. The PCR analysis
is also effective on saliva and nasal secretions (dry
swabs) as well as blood collected into EDTA.
Figure 1: Springbok – Lumpy skin disease with cutaneous nodules
over the face, neck and trunk.(Courtesy Dr Martin Malan)
Histological examination of H&E stained sections
enables detection of the characteristic pathology
of ballooning epidermal degeneration, follicular
epithelial hyperplasia, deep dermal thrombosis
2017
December
17