Careful observation, local or “mild systemic” therapy
In case of single system LCH with unifocal bone involvement of “non-CNS-Risk facial bones” local therapy and careful observation is recommended. The modality of treatment depends on location, size, and symptoms of the disease. Biopsy or curettage is suitable for histopathologic diagnosis and initiating a healing process. Complete excision of bone lesions is not indicated as it may increase the size of the bony defect and the time to healing or result in permanent skeletal defects. Intralesional injection of steroid may hasten healing. Dosages of 40 – 160 mg of methylprednisolone have been used [Yasko et al 1998] (Grade C2 *). Radiotherapy is indicated if there is an impending neurological deficit and a high surgical risk, e.g. lesion in the odontoid peg or cranial base. For multifocal bone LCH and for bone lesions in “special sites” systemic therapy (see next page under front line treatment) should be given. (Grade D2 *)
Isolated lymph nodes involvement
Isolated lymph nodes involvement is rare but spontaneous regressions have been observed. Thus extensive surgery (e.g. neck-dissection) and systemic therapy should be omitted [Lo et al 2009] (Grade C2 *).
- Surgical excision:
Surgical excision should be limited to solitary lesions, but mutilating surgeries such as hemi-vulvectomy should not be performed (Grade D2 *). If the patient is being treated for multisystem disease the skin will respond to treatment. In single system skin disease or in the rare instance where the skin fails to respond fully to systemic treatment for multisystem disease there are a number of treatments directed specifically to the skin:
- Topical nitrogen mustard:
20% nitrogen mustard applied to the skin is an effective treatment in children [Hoeger et al 2000]. There is no published data on treatment in adults and there are problems with availability in most countries. (Grade C1 *)
Psoralen plus ultraviolet A (PUVA) [Sakai et al 1996] and narrow band ultraviolet (UV) B [Imafuku et al 2007] are effective in treating cutaneous LCH in individual case reports. It is difficult to treat patients with intertriginous or scalp involvement and would be contraindicated in penile disease. (Grade C1 *)
Thalidomide is a TNF-α antagonist and has been shown to be effective in treating cutaneous LCH [Sander/Kaatz/Elsner 2004] but gives poor responses in high risk multisystem disease [McClain/Kozinetz 2007]. Dose of 100mg/day in adults is generally used but toxicity with peripheral neuropathy must be monitored (Grade C2 *).
There are no published reports of the use of azathioprine (or its metabolite 6-mercaptopurine) in adults with cutaneous LCH but it is a useful drug in single system skin as well as multisystem disease [Chu 2011]. Patients need to be tested for thiopurine methyl transferase, and if normal should be treated at a dose of 2mg/kg/day. The drug takes about 6 weeks to become effective. (Grade D1 *)
There are published reports on the use of low dose methotrexate as either single agent treatment or in combination with azathioprine or prednisolone. Methotrexate was used successfully at the dosages of 20mg once weekly [Steen et al 2001]. (Grade C1 *)
Involvement of the oral mucous membranes
These lesions should be treated with “mild systemic” therapy as described above and extraction of teeth should be avoided as much as possible. In refractory cases more intensive systemic treatment is required (see Systemic Therapy). (Grade D2 *)
* Grades of recommendation see here.