Pruritus with papulonodul...

A 35-year-old woman presented with a 2-year history of intense pruritus with pain, followed 14 months after onset of the symptoms by the eruption of papulonodular lesions (Figure 1). The patient had no past medical history and was not undergoing any treatment. Initially, bedbugs had been identified at her house, but the pruritus had persisted even after eradication by a professional pest control company. Initially, the laboratory investigation only showed a high IgE rate (272 kU/L; normal < 100 kU/L) and no other abnormal findings on the clinical examination or on the chest X-ray. The patient consulted her gynaecologist as well with no significant findings. Treatment with antihistamines, phototherapy, topical corticoids, and tricyclic antidepressants did not achieve any symptom remission. Only whole-body cryotherapy sessions led to a small improvement of the pruritus.

About 14 months after onset of the symptoms, the patient began to have papulonodular cutaneous lesions. A skin biopsy showed hyperkeratosis with epidermal acanthosis, focal hypergranulosis, and mononuclear infiltrate in the upper dermis, consistent with a chronic nodular prurigo. Patch tests were performed to investigate for cutaneous allergy, but the results could not explain the extensive dermatosis of our patient.

Six months later, she revisited her general practitioner with intractable pruritus, chills, and nagging pain. There was no history of fever, night sweats, or weight loss, but the patient complained of severe tiredness. A physical examination revealed firm and shaped cutaneous nodules from 0.3 to 2 cm in size involving the extensor aspect of the limbs, back, and buttocks. Excoriations and hyperchromic scars from previous nodules were present. A clinical examination did not reveal any adenopathy or hepatosplenomegaly.

Treatment with dexamethasone at 6 mg/day was introduced, and after the corticosteroid therapy the symptoms worsened, with the appearance of a palpable supraclavicular lymphadenopathy. A chest X-ray showed a mediastinal paratracheal mass confirmed by a CT scan, which also revealed several anterior mediastinal, right paratracheal, and right hilar lymphadenopathies.

The laboratory test results were as follows: IgE rate 130.0 kU/L (normal < 100), C-reactive protein 13.38 mg/L (normal < 5), leukocytes 11.9 G/L (normal 4–10), and immunoglobulin M 3.71 (normal 0.40–2.30). Protein electrophoresis showed no anomalies. Serologic tests ruled out hepatitis, HIV, toxoplasmosis, parvovirus B19, syphilis, Epstein-Barr virus, bartonellosis, rickettsioses, Q fever, brucellosis, and tuberculosis infection. A lymph node biopsy revealed a polymorphic lymphoid infiltrate with fibrous bands, as well as the presence of Reed-Sternberg cells, neoplastic cells (CD30, MUM1, PD-L1, and CD20 positive; CD15 negative) and T cells (CD3 positive).