Acrodermatitis continua Hallopeau (ACH) also called as Dermatitis Repens is considered as a rare and severe variant of localized form of palmoplantar pustular psoriasis. This usually is resistant or unresponsive to treatment and may relapse time to time.
Acrodermatitis continua Hallopeau is most commonly seen in middle aged women but may be seen at any age. This may be followed by injury or trauma to the nails, fingers or toes. It is often characterized by eruption of pustules on red scaly base and usually involves the distal phalanges of fingers and toes with frequent involvement of the nail beds. This often results in scarring of skin, degeneration of nail and bone on the affected area.
Initially, it may involve a distal one or two digits. Further, when disease progress it may be generalized over hands, forearm and foot. The skin over the lesion may be red and scaly and multiple pustules may develop. The lesion can be very painful and disabling. Involvement of nail bed and nail matrix often leads to nail dystrophy.
Although it is considered as a variant of pustular psoriasis, as it shares similar histologic features, it doesn’t respond to normal anti-psoriatic medications. Treatment of Acrodermatitis Continua of Hallopeau is very difficult. Although, systemic acitretin is considered as the first-line treatment, results may still vary. As the disease is rare and there are no large scale studies on the treatment approach, specific treatment with successful results is still lacking. Several other treatment modalities have been tried with mixed results. Some of these are; corticosteroids, calcipotriol, adalimumab,[1-3] tretinoin cream, fluorouracil cream, phototherapy (PUVA and UVB), topical tacrolimus and thalidomide. Combination therapy with etanercept and acitretin followed by corticosetroids and acitretin have also been described.References:
 Jennifer A. Sopkovich, Georgann Anetakis Poulos, Henry K. Wong. Acrodermatitis Continua of Hallopeau Successfully Treated with Adalimumab. J Clin Aesthet Dermatol. 2012 February; 5(2): 60–62.
 A.M. Tobin, B. Kirby. Successful treatment of recalcitrant acrodermatitis continua of Hallopeau with adalimumab and acitretin. British Journal of Dermatology,Volume 153, Issue 2, pages 445–446, August 2005.
 Rodica Olteanu,Catalina Iuganu.Successful treatment of acrodermatitis continua of Hallopeau with adalimumab.JAAD,Volume 66, Issue 4, Supplement 1, April 2012, Pages AB203.
 Silpa-archa N, Wongpraparut C.A recalcitrant acrodermatitis continua of Hallopeau successfully treated with etanercept.J Med Assoc Thai. 2011 Sep;94(9):1154-7.