Fixed drug eruption

Case 1020  21.5.14  (H. Diwan)  F 46 HIV+ve.  Arm lesion comes and goes. (*teaching) 

Striking pigmentary incontinence without acute inflammation 

Case 1347   21.8.15  (R. Carr)  F 50 recurrent rash (at same site) (*teaching) 

Interface inflammation; high-lying necrotic keratinocytes; pigment incontinence is present but mild, therefore perhaps not many episodes.  In active phase might expect heavier infiltrate with neutrophils and eosinophils. 

DD:  adult onset Still’s – would expect neutrophils in infiltrate 

         Erythema multiforme – wouldn’t expect pigment incontinence 

Case 1359   8.9.15  (U. Sundram) M 63 recurrent itchy blisters, same site 

Histology was that of erythema multiforme with keratinocyte apoptosis and complete epidermal necrosis.  No pigmentary incontinence.  FDE can be E.M.-like 

Case 1666  14.11.16  (U. Sundram)  F 42 solitary ecchymotic plaque (*teaching) 

Perivascular and periadnexal lymphocytic infiltrate; pigmentary incontinence; apoptotic keratinocytes 

Case 2639  18.8.20 (U. Sundram)  M 28 arm 

Fairly tight perivascular lymphocytic infiltrate in the upper and mid-dermis.  Small focus of parakeratosis with a disturbance of the cytology of the lower epidermis similar to a solar keratosis, but probably secondary to the inflammation.  Some vaculoar change with some colloid bodies and necrosis of the upper epidermis.  No dyskeratosis.  I thought erythema multiforme (see comment on 1359 above), but this was a solitary lesion.