Atrophoderma of Pasini and Pierini

Etiology

The cause of APPi remains unknown. Some authors have linked it to infection with Borrelia burgdorferi.[1] Buechner and Rufi studied sera from 26 patients with typical lesions; 53% had positive IgG antibodies against B burgdorferi compared with 14% of control subjects. No IgM antibodies were detected. Familial cases of APP have been described, but a genetic association has not been confirmed.[1] Although definitive evidence is lacking, a neurogenic cause has been suggested because of the apparent zosteriform distribution of lesions in some cases.[2] There is growing evidence that APP represents a manifestation within the spectrum of localized scleroderma.[3][4]

Several systems have been proposed to classify the clinical types of morphea. The first, suggested in 1995 by Paterson, classifies morphea into 5 subtypes: plaque, generalized, bullous, linear, and deep. Atrophoderma of Pasini and Pierini was included within the plaque-type spectrum, along with morphea en plaque, guttate morphea, keloidal morphea, and lichen sclerosus et atrophicus. Generalized morphea is defined as involving 2 or more body areas. Bullous and linear morphea include linear morphea of the extremities, morphea en coup de sabre, and progressive hemiatrophy. Deep morphea encompasses morphea profunda, subcutaneous morphea, eosinophilic fasciitis, and pansclerotic morphea.

Cases of morphea with a burnt appearance may be atrophic and histologically similar to APP. Plaques of morphea and atrophoderma lesions may occur in the same patient, with atrophic patches appearing in previously normal skin. One case report described a patient with typical APP who developed progressive systemic sclerosis.[5]

Epidemiology

Atrophoderma of Pasini and Pierini is a rare condition, with fewer than 100 cases reported in the literature. It most commonly presents in the second or third decades of life, although onset has been described in both younger and older patients. Congenital cases have also been reported.[2] Atrophoderma of Pasini and Pierini shows a marked female predominance, with a female-to-male ratio of approximately 6:1. It is most commonly reported in White individuals of European descent.

Histopathology

Microscopic findings in APP are generally subtle. In many cases, the epidermis appears normal, although mild atrophy with flattened rete ridges may be observed. The most consistent finding is a reduction in dermal thickness. Collagen changes can include atrophy, sclerosis, fragmentation, and hyalinization.[6] Elastic fiber alterations are variable, and reductions and fragmentation resembling those seen in anetoderma have been reported.[5] Dilatation of superficial blood vessels may be present, often accompanied by a sparse perivascular round-cell inflammatory infiltrate. Sweat glands, pilosebaceous units, and other appendages typically appear normal.

History and Physical

From a clinical perspective, APP is typically asymptomatic and progresses insidiously. Lesions most often first appear on the trunk, particularly the back, and may extend to the chest, arms, and abdomen. Rarely, they may be associated with pain, pruritus, or paresthesia.

The condition is characterized by single or multiple irregular round patches that vary in size from a few millimeters to several centimeters.[3] Lesions are slightly depressed relative to the surrounding skin, with sharply demarcated, cliff-drop–like borders. Unlike morphea, an erythematous or lilac-ring border is absent. Lesions are usually hyperpigmented; however, Saleh et al reported in a retrospective study of 16 Lebanese patients that 56% of lesions were hypopigmented and 25% were flesh-colored.[5]

A lack of inflammatory features is typical. Lesions do not exhibit sclerosis or induration on palpation, and the surrounding skin appears normal. Lesions are often bilateral, though unilateral zosteriform or Blaschkoid patterns have been documented.[3]

Evaluation

Evaluation of APP may include serologic testing, imaging, dermatoscopy, and histopathology in select cases. An enzyme-linked immunosorbent assay can be performed to detect anti–B burgdorferi antibodies. Thickness of the lesions and the surrounding skin can be assessed with magnetic resonance imaging or 13-MHz B-mode ultrasonography to document dermal atrophy, although such imaging is often unnecessary. Dermoscopy is not routinely performed; however, a recent case report of a 50-year-old patient demonstrated a violaceous pigmented network sparing the perifollicular region, predominant perifollicular brownish pigmentation, and white dots.[7][8]

Histopathologic changes are generally minimal, with reduced dermal volume relative to normal skin. Additional findings may include varying degrees of collagen homogenization and clumping in the mid and reticular dermis, interstitial edema, and a mild perivascular infiltrate of lymphocytes and histiocytes. Sweat glands, pilosebaceous units, and other appendages are typically normal. The overlying epidermis is usually unremarkable but may exhibit mild atrophy with flattened rete ridges.

Treatment / Management

No treatment has been consistently effective for APP. Patients with a positive B burgdorferi antibody titer sometimes respond to tetracyclines. Doxycycline (200 mg/d) has been reported to prevent the appearance of new lesions; however, the overall efficacy of antibiotics in seropositive patients remains inconclusive. In a retrospective study of 25 patients treated with either oral penicillin (2 million IU/d) or oral tetracycline (500 mg three times daily) for 2 to 3 weeks, 20 patients showed clinical improvement. Notably, 4 of 6 untreated patients in the same study did not develop progressive disease.[9] (B3)

Other therapeutic approaches include topical corticosteroids and antimalarials such as hydroxychloroquine, which may be beneficial in cases associated with lupus. Topical calcineurin inhibitors have also been used, though responses are variable.[10] Laser therapy with a Q-switched alexandrite laser has been reported to improve hyperpigmented lesions.[11] A recent case report described a patient with long-standing APP who responded positively to treatment with methylprednisolone acetate, representing a novel therapeutic approach in this condition.[12](B3)

Differential Diagnosis

Atrophoderma of Pasini and Pierini closely resembles several other conditions and must be distinguished from atrophoderma of Moulin, anetoderma, lichen sclerosus, morphea, and postinflammatory hyperpigmentation.

Prognosis

Atrophoderma of Pasini and Pierini typically progresses over 10 to 20 years. Eventually, disease activity stabilizes, but existing lesions generally do not resolve. Progression to systemic sclerosis is extremely rare. One reported case by Bisaccia et al in 1982 described a 42-year-old woman with typical lesions on the back who subsequently developed progressive systemic sclerosis, including Raynaud phenomenon, sclerodactyly, and pulmonary fibrosis.[13]

Complications

Complications of APP are primarily cosmetic and psychological, as the condition is benign and nonprogressive. Persistent depressed, hyperpigmented patches can cause noticeable disfigurement, leading to reduced self-esteem and psychosocial distress, particularly in young patients.[14] Residual dyspigmentation and textural changes often persist long-term. Rarely, overlap with morphea may occur, suggesting potential progression to localized sclerosis. There is no risk of malignancy or systemic involvement; however, misdiagnosis may result in unnecessary interventions.[15]