DP14 Spectrum of atrophoderma unveiled through clinicopathological correlation

Abstract Atrophoderma of Pasini and Pierini (APP) and atrophoderma of Moulin (AoM) are rare dermatoses characterized by hyperpigmented, atrophic, nonindurated plaques. Previously classified as a subtypes of morphoea, these have distinct clinicopathological features. We herein present two intriguing clinical cases of atrophoderma wherein histology played a pivotal role in establishing a definitive diagnosis. A 24-year-old man reported a 5-year history of asymptomatic, darkened patches on his back, gradually increasing in size. Examination revealed a solitary hyperpigmented plaque with ‘cliff-drop’ borders on the back, 5 × 8 cm in size, without overlying skin surface changes. Histology demonstrated epidermal atrophy, reduced dermal thickness, mild perivascular lymphocytic infiltrate and no fibrosis, consistent with diagnosis of APP. The patient was reassured about the benign nature of APP. Emollients and mild corticosteroids were prescribed. Our second case was a 26-year-old man presenting for evaluation of multiple asymmetrical, brownish, atrophic patches predominantly on the trunk. The lesions first appeared in adolescence and had progressively spread over 5 years. The patches were sharply demarcated, nonscaly and arranged along the lines of Blaschko. There was no associated pain, binding pruritus or systemic involvement. Dermatological examination revealed hyperpigmented, atrophic plaques with a ‘cliff-drop’ border along the lines of Blaschko in an ‘S-shaped’ configuration with absent erythema or sclerotic change. Routine laboratory investigations, including autoimmune and inflammatory markers, were within normal limits. A skin biopsy showed epidermal thinning, reduced dermal collagen and no significant inflammatory infiltrate, consistent with AoM. The patient was treated conservatively with emollients. Regular dermatological follow-ups were scheduled to monitor for potential progression or associated conditions. The Table characterizes differentiating pointers for the subtypes of atrophoderma, emphasizing the role of histology in formulating a diagnosis.TableDifferentiating factors in atrophoderma Atrophoderma of Pasini and PieriniAtrophoderma of MoulinAtrophoderma vermiculatumDefining featureRare dermatosis with hyperpigmented, atrophic plaquesRare subtype of atrophoderma with Blaschko-linear distributionRare follicular atrophoderma presenting as a ‘worm-eaten’ appearanceAge of onsetYoung adulthood to mid adulthoodAdolescence to early adulthoodChildhood or early adolescenceClinical featuresHyperpigmented, atrophic plaques with ‘cliff-drop’ borders, over trunk or limbsAsymmetrical, brownish atrophic plaques in Blaschko linesMultiple follicular depressions creating a honeycomb or vermiculated pattern, predominantly over the faceHistopathologyEpidermal thinning, reduced dermal thickness, mild perivascular lymphocytic infiltrate, no fibrosisEpidermal thinning, reduced dermal collagen, no significant inflammatory infiltrateFollicular plugging, perifollicular fibrosis and dilated folliclesAetiologyUnclear; possibly mild inflammation or immune mechanismsLikely due to somatic mosaicism or genetic predispositionUnknown; genetic predisposition (autosomal dominant) suspectedProgressionSlowly progressive, often stabilizesSlowly progressive, often stabilizesGradually progressive