Past exam of the medicine course of the University of Oxford / 1865 / Second examination / Pathology / 8

Give the differential diagnosis between Syphilis in the infant, Varicella, Varioloid, and Variola, as usually described.

Infantile syphilis, varicella, modified smallpox and ordinary smallpox are distinguished by the whole illness: age and history, prodrome, distribution, lesion depth, successive crops and the speed of evolution. No isolated “spot” supplies an infallible diagnosis. Varioloid is the historical name for modified smallpox, particularly after vaccination; it is not a synonym for varicella.

In an infant, the relevant syphilis is chiefly congenital syphilis, transmitted during pregnancy. It can be unapparent at birth and declare itself later with persistent nasal discharge or “snuffles,” poor growth, fissuring near the mouth, a copper-coloured maculopapular or peeling eruption, and lesions on palms and soles. Bullae or pustular appearances can occur. Associated hepatosplenomegaly, jaundice and painful bone disease support a systemic process rather than a simple crop of transient vesicles. The eruption is not required to pass synchronously through the stereotyped smallpox sequence. Maternal infection and appropriate serology matter; absence of a rash at birth does not exclude infection.^[ref][ref]

Varicella, or chickenpox, typically produces delicate superficial itchy vesicles on a red base, especially on the anatomical trunk, with successive crops. Consequently fresh papules, vesicles and crusts coexist in one area. In children the preceding illness is often mild or absent. Individual lesions evolve quickly, and ordinary superficial lesions usually heal without the deep pitting associated with destructive smallpox lesions, although secondary infection can scar. The distribution is generally centripetal rather than most dense on the distal limbs; palms and soles are much less commonly affected.^[ref]

Ordinary variola, or smallpox, classically begins with a marked febrile prodrome, often including headache, backache and prostration, before the rash. Lesions favour the face and extremities, can affect palms and soles, and proceed through firm papules to deep-seated vesicles and pustules, often with central depression. Within a given region they are relatively alike in developmental stage. The lesions evolve over days rather than the rapid successive crops of varicella; crusting and separation may leave depressed scars. Severe confluent, flat or haemorrhagic forms depart from the uncomplicated textbook pattern, so the absence of perfect pustules is not a universal exclusion.^[ref][ref]

Varioloid retains the cause of smallpox but has a modified course. Prior vaccination can yield fewer and more superficial lesions, faster evolution and less secondary fever. The prodrome can still be substantial. Sparse lesions and shortened evolution can resemble chickenpox, so vaccination history and the entire time course help, but neither a vaccination scar nor mild disease proves the diagnosis. Varioloid and variola belong on a spectrum of the same infection, whereas varicella is caused by a different virus.^[ref]

Thus the characteristic contrast is persistent multisystem infantile infection for congenital syphilis, superficial lesions in mixed-stage crops for varicella, deeper regionally synchronous lesions with a severe preceding fever for ordinary smallpox, and attenuation of the latter pattern for varioloid. Current confirmation uses tests appropriate to the suspected organism; the historical clinical distinctions remain valuable descriptions, but they do not replace modern laboratory confirmation.