Plate 7

Prurigo [Definition: A disease of the skin, of which intense itching is the chief symptom.]

‘The symptom of itching is common ... to many diseases of the skin. There are, however, some cases where it occurs as the leading circumstance, and where it is accompanied with an eruption of papulae, the colour of which does not much differ from that of the adjoining cuticle ...

‘The prurigo mitis [figure 1] ... is characterised by soft and smooth papulae ... They are not ... accompanied with tingling, but with an almost incessant itching: this is ...felt more particularly on undressing, and it often prevents rest for some hours after getting into bed ... In the first stage ... I have in general prescribed sulphur internally, every morning and evening, for about a fortnight ... The parts affected should be often washed with tepid water ...

‘The prurigo formicans [figure 2] is a much more obstinate and troublesome disease ... Itching is not the only source of uneasiness ...Patients have sometimes a sensation as if small insects were creeping on the skin, sometimes as if stung all over by ants ... sometimes as if hot needles were piercing the skin in different places ... this species of prurigo is very generally the effect of some constitutional disease ... I may add the want of proper cleanliness. Certain modes of diet have likewise a considerable effect ... An eruption similar to that represented often takes place in children who handle dogs or cats affected with the mange, also in men who wash mangy hogs.

‘The prurigo senilis [figure 3] does not differ much ... from the prurigo formicans ... In one case ... I accidentally discovered ... a number of insects, so minute, and so quick in their motions, as not to be discernible without considerable attention [figure 4] ... the present case ... tends to confirm the supposition that the prurigo senilis and prurigo formicans may be generally owing to cutaneous insects.’