Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.
Since this is one of the most resistant skin infections, a multiple combination of therapies is required. I suggest you to discuss with your
dermatologist about all these therapies which im going to mention.
Local treatments:
These include:
1. Emollients - use frequently to cool and soothe itchy skin; menthol may be added to supplement this effect.
2. Steroids are used to decrease inflammation and pruritus and to soften and smooth nodules, usually topically or under occlusive dressings but may be given intralesionally or orally. Response is often variable.
3. Intranodular steroid injections are sometimes used.
4. Phenol and
local anaesthetic creams have also been found to be helpful.
5. Coal tar ointment is sometimes used as an alternative to steroids.
6. Calcipotriol ointment is sometimes more effective than topical steroids.
7. Capsaicin cream induces itching and burning and ultimately may stop itch. It requires repeated applications 4-6 times daily.
8. Cryotherapy with liquid nitrogen can shrink the nodules and reduce their itch.
9. Pulsed dye laser may reduce the vascularity of individual lesions.
Systemic therapies:
These include:
1. Antihistamines may help to control itch in some cases.
2. Thalidomide has been shown to be quite effective in severe cases but carries a teratogenic and peripheral neuropathic risk.
3. Opiate-receptor antagonists, such as naltrexone, have shown some efficacy in treating itch.
4. Systemic retinoids, such as acitretin, may shrink the nodules and reduce itching.
5. Psoralen combined with ultraviolet A (PUVA) treatment may help but carries the risks of prolonged UV exposure.
6. There is anecdotal evidence of good response, in severe, refractory cases, to the immunomodulatory macrolide,
roxithromycin, either alone, or combined with the anti-fibroblast agent, tranilast.
7. The immunomodulators tacrolimus and
pimecrolimus have been found to be beneficial in small studies of steroid-unresponsive patients and patients with thin skin.
8. Gabapentin has been used to good effect. It can, however, cause sedation.
Psychological distress and depression in predisposed subjects may play a key role in inducing a pruritic sensation, leading to the scratching that perpetuates the condition (the 'itch/scratch cycle'). As with
lichen simplex chronicus, it is thought that psychological factors play a role in causing and maintaining both conditions. One study found that anxiety and depression were common in
prurigo nodularis patients.
Approaches to address the psychodermatology include:
1. Cognitive behavioural therapy (CBT). However, there is little evidence of efficacy and patients must be open to a psychological model of their problem to have a good chance of responding
2. Habit reversal therapy, originally developed to treat tics, has been used to break the 'itch/scratch' cycle
3. Anxiolytic drugs may be helpful but there is a danger of dependence. Similarly, antidepressants such as
amitriptyline or doxepin may be useful.
Hope I have answered your query. Let me know if I can assist you further.