Dermatitis: Difference between revisions

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Mikael Häggström (talk | contribs)
Mikael Häggström (talk | contribs)
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*Epidermal changes are less common in lichenoid drug eruptions when compared to classic lichen planus. However, a higher concentration of necrotic keratinocyte and eosinophils in the infiltrate can be helpful in distinguishing lichenoid drug reaction from cutaneous lichen planus. A lengthy interval between the commencement of drug therapy and the onset of lesions does not exclude a diagnosis of lichenoid drug reaction. Resolution of the lesions often occurs within weeks to months after discontinuation of the offending drug.<ref name="GorouhiDavari2014"/>
*Epidermal changes are less common in lichenoid drug eruptions when compared to classic lichen planus. However, a higher concentration of necrotic keratinocyte and eosinophils in the infiltrate can be helpful in distinguishing lichenoid drug reaction from cutaneous lichen planus. A lengthy interval between the commencement of drug therapy and the onset of lesions does not exclude a diagnosis of lichenoid drug reaction. Resolution of the lesions often occurs within weeks to months after discontinuation of the offending drug.<ref name="GorouhiDavari2014"/>
| [[File:Histopathology of lichenoid drug reaction.jpg|190px]] ||  
| [[File:Histopathology of lichenoid drug reaction.jpg|190px]] ||  
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! Lichen nitidus
! Lichen nitidus
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*Thinning of overlying epidermis and downward extension of the rete ridges at the lateral margin of the infiltrate, resulting in a typical "claw clutching a ball" appearance.<ref name="Mutairi">{{cite journal |vauthors=Al-Mutairi N, Hassanein A, Nour-Eldin O, Arun J |title=Generalized lichen nitidus |journal=Pediatr Dermatol |volume=22 |issue=2 |pages=158–60 |year=2005 |pmid=15804308 |doi=10.1111/j.1525-1470.2005.22215.x |url=}}</ref>
*Thinning of overlying epidermis and downward extension of the rete ridges at the lateral margin of the infiltrate, resulting in a typical "claw clutching a ball" appearance.<ref name="Mutairi">{{cite journal |vauthors=Al-Mutairi N, Hassanein A, Nour-Eldin O, Arun J |title=Generalized lichen nitidus |journal=Pediatr Dermatol |volume=22 |issue=2 |pages=158–60 |year=2005 |pmid=15804308 |doi=10.1111/j.1525-1470.2005.22215.x |url=}}</ref>
| [[File:Histopathology of lichen nitidus.jpg|190px]] || [[File:Photography of lichen nitidus.jpg|190px]]
| [[File:Histopathology of lichen nitidus.jpg|190px]] || [[File:Photography of lichen nitidus.jpg|190px]]
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! Lichen amyloidosus
| Presence of amyloid, possibly with direct immunofluorescence and Congo red staining.<ref name="ShenoiBalachandran2005">{{cite journal|last1=Shenoi|first1=SD|last2=Balachandran|first2=C|last3=Mehta|first3=VandanaRai|last4=Salim|first4=T|title=Lichen amyloidosus: A study of clinical, histopathologic and immunofluorescence findings in 30 cases|journal=Indian Journal of Dermatology, Venereology and Leprology|volume=71|issue=3|year=2005|pages=166|issn=0378-6323|doi=10.4103/0378-6323.16230}}</ref>
| [[File:Histopathology of lichen amyloidosis with Congo red.jpg|thumb|190px|Congo red.]]
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Interface dermatitis with lichenoid inflammation, not otherwise specified, can be caused by lichen planus-like keratosis, lichenoid actinic keratosis,  lichenoid lupus erythematosus, lichenoid GVHD (chronic GVHD), pigmented purpuric dermatosis, lichen amyloidosus, pityriasis rosea, and pityriasis lichenoides chronica.<ref name="Alsaad2005"/> Unusual conditions that can be associated with a lichenoid inflammatory cell infiltrate are HIV dermatitis, syphilis, mycosis fungoides, urticaria pigmentosa, and post-inflammatory hyperpigmentation.<ref name="Alsaad2005"/> In cases of post-inflammatory hyperpigmentation, it is important to exclude potentially harmful mimics such as a regressed melanocytic lesion or lichenoid pigmented actinic keratosis.<ref name="Alsaad2005"/>
Interface dermatitis with lichenoid inflammation, not otherwise specified, can be caused by lichen planus-like keratosis, lichenoid actinic keratosis,  lichenoid lupus erythematosus, lichenoid GVHD (chronic GVHD), pigmented purpuric dermatosis, lichen amyloidosus, pityriasis rosea, and pityriasis lichenoides chronica.<ref name="Alsaad2005"/> Unusual conditions that can be associated with a lichenoid inflammatory cell infiltrate are HIV dermatitis, syphilis, mycosis fungoides, urticaria pigmentosa, and post-inflammatory hyperpigmentation.<ref name="Alsaad2005"/> In cases of post-inflammatory hyperpigmentation, it is important to exclude potentially harmful mimics such as a regressed melanocytic lesion or lichenoid pigmented actinic keratosis.<ref name="Alsaad2005"/>