Herald patch is seen:
Ans: (b) Pityriasis roseaRef: Rook's Textbook of Dermatology, 8th edition, Page 33.78PITYRIASIS ROSACEAAlso known as Gilbert's disease, six-week diseasePapulosquamous disorder with pruritic or asymptomatic lesionsCommon in adolescents and young adultsRisk factorsViral-HHV-6, HHV-7Drugs-Metronidazole, Captopril, GoldInitial 'herald or mother' patch* 1-2 cms oval plaque on trunk followed by daughter patches two weeks laterChristmas tree pattern* along lines of cleavage with a peripheral collarette of scale producing the Hanging curtain sign when stretched.No oral lesions.Self-limiting.OTHER OPTIONSPityriasis rubra pilarisCircumscribed follicular keratosisBranny scaleOrange-red erythemaPalmoplantar keratodermaIf erythroderma develops there will be islands of normal uninvolved skin.Lichen planusViolaceous polygonal pruritic papules more on the flexural aspects.The lesions show minimal scaling,Wickham's striae may be seen,The mucosa may be involved,Hair and nails also can be involved.PsoriasisErythematous plaques with silvery white plaques which are seen more on the extensor aspects.Auspitz sign will be positive.Scalp scaling is commonly seen.Palms and soles may show scaling and Assuring.Nails may be involved.Psoriatic arthropathy may affect the joints.
Psoriasis
Pityriasis rosea
Lichen planus
Pityriasis rubra pilaris
Papulosquamous Disorders