A 14 years old girl with rare chronic skin disease Prurigo Nodularis PN 结节性痒疹

A 14-year-old girl presented at Tangs Clinical Centre in 2004 because multiple, firm, dome-shaped nodules -several millimeters to 1 centimeter- developed on her arms and legs. Persistent itching and scratching had occurred over 4 years. The affected areas were eroded, excoriated and some even ulcerated as the patient frequently dug into them with her fingernails (Fig.1).

Four years earlier, the above patient—a school student—was otherwise well. When she first complained of some itchiness on her legs, her parents thought it was just due to a mosquito bite, but gradually, the papules had spread throughout the legs and arms. The patient was treated with non-steroidal antipruritic preparations (menthol and pramoxine) which did not improve her appearance. She was given antihistamines (hydroxyzine) and topical corticosteroids, but showed no improvement.

The patient had no history of allergic rhinitis or atopic dermatitis, and there were no other siblings in her family. There were no pets in her house, and her parents were not smokers. During the physical examination, the patient was evidently uncomfortable and was scratching continuously at her skin. Her temperature was 37.5°C, pulse 90, respiratory rate 24, blood pressure 70/98 mmHg. The hyperkeratotic, firm nodules varied in size from 0.5 to 2.0 cm, and some were excoriated. Skin culture and KOH was negative. She was administered Tangs Derma-zema capsules, 1440 mg three time a day. The patient she responded to the Herose treatment with marked improvement (Fig.2-Fig.6).

No other therapy apart from TANGS was given to the patient because of the continuing response and improvement; the firm nodulars were completely cleared at the end of month 12.

Prurigo Nodularis (PN)

Prurigo Nodularis PN is a chronic dermatosis of unknown etiology characterized by discrete, intensely pruritic, symmetric, papulonodular lesions primarily on the extensor surfaces of the extremities, The abdomen and sacrum are the next most common sites of involvement in one study. The face and palms are rarely involved. It may occur in human immunodeficiency virus (HIV) disease. PN usually occurs in younger or middle-aged females with atopy, but also in the absence of atopy. It starts with piercing pruritus that leads to picking and scratching. Lesions persist for months after the trauma ends. The nodules are sometimes hyperkeratotic and often excoriated. Consistency is firm, and the nodules may be mistaken for common warts. The differential diagnosis can be seen in Fig.7. The standard treatment of PN includes antihistamines, ultraviolet light, and topical and systemic corticosteroids; unfortunately PN is notoriously resistant to conventional therapy.

Differential Diagnosis of Prurigo Nodularis

  • Perforating disease
  • Hypertrophic lichen planus
  • Pemphigoid nodularis
  • Actinic prurigo
  • Multiple keratoacanthomas
  • Consider
  • Nodular scabies
  • Dermatitis herpetiformis

PN was first described by Hyde in 1909, and was also known as nodular prurigo. At the microscopic level, increased numbers of Merkel cells are also seen adjacent to the dermal nerve fibers and mast cells in prurigo nodularis. It is thought that this complex may mediate the abnormally heightened perception of touch and itch in these patients. Nerve growth factor is overexpressed in prurigo nodularis lesions, and it has been implicated in the pathogenesis of the characteristic cutaneous neural hyperplasia seen. Nerve growth factor is produced and released by mast cells, which are increased in number and size on histologic sections. It upregulates the expression of neuropeptides, such as calcitonin gene-related peptide and substance P. These are thought to mediate inflammation and itch.


Herbal medicines like TANGS, make use of plants to treat disease, either via a single herb or via a mixture of different herbs. Unlike conventional drugs, in which the active substance is extracted from the herb, herbal medicines usually makes use of a herb in its whole form, therefore making it difficult to determine which ingredient or ingredients are considered the active components, and difficult to subject herbal medicines to standardization.

Although we do not yet know the exact mechanism of action responsible for the positive clinical response to TANGS therapy, nor understand its ability to modulate pathologic cellular and inflammatory pathways in skin lesions, the treatment results (especially in PN patients and previous clinical findings) suggest that TANGS may manage not only T-cells but also DCs and a spectrum of Type 1 inflammatory genes. These case reports may provide an opportunity to PN patients to consider an alternative to conventional immunosuppressive drugs.