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Acquired Beauty Mark?

New Black Macule on the Face
      An otherwise healthy young female patient presented with a new asymptomatic black lesion on her left upper cutaneous lip that developed shortly after spending time in the garden. Clinical examination revealed a 4-mm well-circumscribed black circular macule without associated inflammation (Figure 1). Due to concern for an atypical melanocytic lesion, a punch biopsy was performed. Histopathologic examination disclosed full-thickness epidermal necrosis with an underlying band of neutrophilic inflammation with karyorrhexis (Figure 2). Clinicopathologic features supported a diagnosis of black-spot (Toxicodendron) dermatitis, sans dermatitis.
      Black-spot dermatitis occurs when urushiol from the sap of plants in the Toxicodendron family (often poison ivy, poison oak, or poison sumac) is liberated, oxidizes, and deposits on the skin.
      • Kurlan J.G.
      • Lucky A.W.
      Black spot poison ivy: a report of 5 cases and a review of the literature.
      • McClanahan C.
      • Asarch A.
      • Swick B.L.
      Black spot poison ivy.
      • Guin J.D.
      The black spot test for recognizing poison ivy and related species.
      The shiny, jet-black macules that form may be accompanied by allergic contact dermatitis,
      • Kurlan J.G.
      • Lucky A.W.
      Black spot poison ivy: a report of 5 cases and a review of the literature.
      ,
      • McClanahan C.
      • Asarch A.
      • Swick B.L.
      Black spot poison ivy.
      ,
      • Hurwitz R.M.
      • Rivera H.P.
      • Guin J.D.
      Black-spot poison ivy dermatitis: an acute irritant contact dermatitis superimposed upon an allergic contact dermatitis.
      ,
      • Koo B.
      • Lieb J.A.
      • Garzon M.C.
      • et al.
      Five-year-old boy with a diffuse erythematous rash with black crusts. Diagnosis: black spot poison ivy (Rhus dermatitis).
      a feature absent in the patient presented here. We speculate that this patient may be among the minority of Americans who is not sensitized to Toxicodendron.
      • Koo B.
      • Lieb J.A.
      • Garzon M.C.
      • et al.
      Five-year-old boy with a diffuse erythematous rash with black crusts. Diagnosis: black spot poison ivy (Rhus dermatitis).
      Although biopsy is not usually necessary for diagnosis, histopathologic features associated with the irritant response to urushiol include epidermal necrosis with neutrophilic inflammation. When present, an accompanying allergic contact dermatitis also confers epidermal spongiosis and perivascular mixed inflammation with eosinophils histopathologically
      • Hurwitz R.M.
      • Rivera H.P.
      • Guin J.D.
      Black-spot poison ivy dermatitis: an acute irritant contact dermatitis superimposed upon an allergic contact dermatitis.
      and is generally accompanied by significant pruritus clinically. Although the black deposits cannot be removed with conventional cleaning, they generally wear away within about 1 week.
      • Kurlan J.G.
      • Lucky A.W.
      Black spot poison ivy: a report of 5 cases and a review of the literature.
      ,
      • McClanahan C.
      • Asarch A.
      • Swick B.L.
      Black spot poison ivy.
      ,
      • Koo B.
      • Lieb J.A.
      • Garzon M.C.
      • et al.
      Five-year-old boy with a diffuse erythematous rash with black crusts. Diagnosis: black spot poison ivy (Rhus dermatitis).
      Recognition of this entity is important for appropriate patient counseling and reassurance.
      Figure thumbnail gr1
      Figure 1Black spot dermatitis. A 4-mm well-demarcated circular black macule developed abruptly on the left upper cutaneous lip following time spent in the garden.
      Figure thumbnail gr2
      Figure 2Histopathology of black spot dermatitis. Biopsy of the involved skin revealed full-thickness epidermal necrosis and a localized neutrophilic infiltrate with leukocytoclasis. Surface oleoresin was not prominent. (Hematoxylin-and-eosin stain, original magnification x 20).

      References

        • Kurlan J.G.
        • Lucky A.W.
        Black spot poison ivy: a report of 5 cases and a review of the literature.
        J Am Acad Dermatol. 2001; 45: 246-249
        • McClanahan C.
        • Asarch A.
        • Swick B.L.
        Black spot poison ivy.
        Int J Dermatol. 2014; 53: 752-753
        • Guin J.D.
        The black spot test for recognizing poison ivy and related species.
        J Am Acad Dermatol. 1980; 2: 332-333
        • Hurwitz R.M.
        • Rivera H.P.
        • Guin J.D.
        Black-spot poison ivy dermatitis: an acute irritant contact dermatitis superimposed upon an allergic contact dermatitis.
        Am J Dermatopathol. 1984; 6: 319-322
        • Koo B.
        • Lieb J.A.
        • Garzon M.C.
        • et al.
        Five-year-old boy with a diffuse erythematous rash with black crusts. Diagnosis: black spot poison ivy (Rhus dermatitis).
        Pediatr Dermatol. 2010; 27: 395-396