Ptyrass rosea

Ptyrass rosea s a common acute self-lmtng dsease affectng chldren and young adults. After beng unwell, a typcal ‘herald patch’ follows whch s a large, 2-5 cm, nflamed well-defned scaly patch. A general erupton wth new oval, pnk to red fne scaly patches occurs 1-2 weeks later wth collarette of scale surroundng the edge (Fgure 15.5). These lesons can occur n a Chrstmas tree pattern occurrng manly on the trunk, neck and upper thrd of the arms and legs. The skn erupton fades wthn 3-6 weeks and can usually be dagnosed from the typcal hstory and herald patch. Dfferentals nclude seborrhoec dermatts, drug erupton, secondary syphls, urtcara and guttate psorass. Only mnmal treatment s needed wth topcal emollents, mld to moderate strength topcal sterods and, f not responsve, UVB.

Key ponts

•  Lchen planus has many clncal patterns ncludng mucosal.

•  Lchenod drug reactons can mmc lchen planus.

•  Ptyrass rosea s an acute self-lmtng dsease n chldren and young adults.


Graft versus host dsease should be consdered n any lchenod skn erupton n severe haematologcal condtons.

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  • Category: Skin, nails, hair