What are the Factors That Induce Paradoxical Hypertrichosis After Laser Hair Removal?

BACKGROUND: Laser hair removal (LHR) is one of the most requested cosmetic procedures worldwide. A rare side effect is the appearance of excess hair around previously treated areas, known as paradoxical hypertrichosis. OBJECTIVES: The aim of this study was to retrospectively identify the cause of this side effect. METHODS: This study included all patients who underwent LHR at our center between November 2018 and November 2020. Alexandrite laser hair removal (HR) or diode laser super hair removal (SHR) was performed in 70% and 30% of cases, respectively. Clinical features and daily habits of patients with and without postlaser hypertrichosis were compared. RESULTS: Of the 7381 patients who received LHR, 25 patients (0.34%) demonstrated an increase in hair growth compared to baseline. Of these 25 patients, 24 had been treated with alexandrite laser HR (P < .01). The most common site was the upper arm, followed by the periareolar area. Daily sun protection was associated with a significantly lower incidence of hypertrichosis (P < .05), as was confirmed and shown to be independent of Fitzpatrick skin type by binary logistic regression analysis (odds ratio = 0.41, P < .05). CONCLUSIONS: In our clinic, we observed paradoxical hypertrichosis after laser hair removal in a small minority of cases, as described by others. We did not observe differences in incidence related to skin type, but daily sun protection and LHR with diode laser SHR were associated with significant reductions in incidence rates. In addition to previously reported common sites, we also identified the periareolar area as a high-risk region.

Juvenile Dermatomyositis With Rare Cutaneous Manifestation: Generalised Hypertrichosis.

Juvenile dermatomyositis (JDM) is a rare autoimmune disease characterised by inflammation of muscles and skin with extra muscular involvement of joints, heart, intestine, and liver. Pathogenesis of JDM is believed to be due to vasculopathy. Along with classic cutaneous features of JDM, rare findings include hypertrichosis, lipoatrophy, photosensitivity, bullous lesions, and hyperhidrosis. We present, here, a case of JDM with hypertrichosis as very few cases have been reported previously.

An update on Becker's nevus: Pathogenesis and treatment.

Becker's nevus (BN) manifests as a hyperpigmented, sometimes hypertrichotic plaque/patch over the chest and shoulder, and it is in the category of benign cutaneous hamartomas. BN has elongation and fusion of the rete ridge, keratotic plugging, sebaceous hyperplasia, smooth muscle hyperplasia, and hyperpigmentation of the basal/suprabasal layer histologically. This article highlights all issues involved in pathogenesis and treatment options of BN. According to current research, postzygotic ACTB mutations induce BN and Becker's nevus syndrome (BNS). Although several therapy strategies were utilized to treat the pigmentary and hypertrichotic aspects of BN, no definitive standard treatment was identified to far, and further research is needed to better educate BN care.

New-onset cutaneous nodule arising from hypertrichotic brownish patch in a 6-year-old girl.

A 6-year-old girl presented with an enlarging asymptomatic nodule within a hyperpigmented hypertrichotic patch on her left thigh. Histopathological examination revealed tumour cells with round to fusiform nuclei in a fine fibrillary collagenous stroma, along with increased cellularity. Most of the tumour cells were positive for S-100 and negative for HMB-45 and Melan-A.

Hair disorders in cancer survivors.

With increasing survival rates across all cancers, survivors represent a growing population that is frequently affected by persistent or permanent hair growth disorders as a result of systemic therapies, radiotherapy, surgical procedures, and therapeutic transplants. These hair disorders include persistent chemotherapy-induced alopecia, persistent radiotherapy-induced alopecia, endocrine therapy-induced alopecia and hirsutism, postsurgery alopecia and localized hypertrichosis, and persistent stem cell transplantation and targeted therapy-induced alopecia. The information contained in this continuing medical education series should facilitate a better understanding on hair disorders in cancer survivors so that adequate support and therapies may be provided.

Acquired Localized Hypertrichosis Following Pressure Garment and/or Silicone Therapy in Burn Patients.

Hypertrichosis is characterized by excessive and abnormal hair growth anywhere on the skin and may develop after prolonged local irritation, such as application of a cast, injury, or a bite. Pressure garment/silicone therapy is often used to prevent hypertrophic scar formation. The adverse effects of gel sheet application include rash, skin breakdown, cessation of scar responsiveness, pruritus, contact dermatitis, and dry skin. We report on 7 burn patients who developed hypertrichosis following application of pressure garment/silicone therapy to prevent hypertrophic scarring.

Long-term outcome of a patient with paradoxical hypertrichosis after laser epilation.

One underreported, rare side effect of laser hair removal is paradoxical hypertrichosis. It is largely unknown what the long-term outcomes are of patients who develop this complication. We report a 21-year-old, Fitzpatrick II, male patient, who had patchy areas of dark hair affecting various body areas. An Alexandrite 755 nm laser was used to address the desired areas at energies between 20 and 22 J/cm2 at 10-12-week intervals over a course of seven treatments. After three treatments, the patient noted a significant increase in the density and length of hairs involving the back, shoulders, neck, and upper arms. The patient was followed on a biannual basis, without further epilatory intervention. After 10 years, the areas of paradoxical hair growth were sparser compared to immediate post-treatment but remained denser compared to pre-treatment. This case illustrates improvement in the condition over time without intervention. Further studies are needed to determine the etiopathogenesis of this phenomenon.

Localized hypertrichosis of intermammary cleft in monozygotic twins.

Hypertrichosis is a condition in which hair is longer and denser than what is considered normal for an individual based on age, sex, ethnicity, and location on the body and can be classified based on its distribution (generalized vs localized), age of onset (congenital vs acquired), and type of hair (lanugo or vellus vs terminal). We describe a rare case of monozygotic female twins who presented for localized hypertrichosis of the intermammary cleft that developed during puberty. Endocrine examination was unremarkable. Discussion of various treatment modalities should be considered, because localized hypertrichosis may have a considerable psychosocial effect.

Is paradoxical hair growth caused by low-level radiant exposure by home-use laser and intense pulsed light devices?

INTRODUCTION AND OBJECTIVES: This qualitative review of paradoxical hair growth, following professional treatments reviews, clarifies whether low fluence is the most probable cause of unwanted hair regrowth after at home light-based treatments. MATERIALS AND METHODS: The proposed causes of unexpected hair regrowth are examined, and our scientific understanding of absorption and scattering of light in turbid tissue is reviewed. Published reports of paradoxical hair growth are assessed. RESULTS: Early laser hair removal studies failed to record the occurrence of hair induction despite the significant numbers of subjects treated. Neither published paradoxical hair growth studies following home-based laser or intense pulsed light (IPL) hair removal treatments, nor randomised or controlled studies documenting paradoxical hair growth following professional treatments could be found. Several authors directly proposed inflammatory response to be the primary cause of hair growth induction. CONCLUSIONS: It is unlikely that hair regrowth several centimetres or more away from the irradiated tissue can be attributed to the laser or IPL used. In many cases of paradoxical hair growth, other causes may be responsible for the unexpected hair growth. The primary cause of instances of 'true' paradoxical hair growth is probably limited to darker phototypes with one or more other characteristics including polycystic ovarian syndrome or other androgen hormonal irregularities following high energy treatments with the corresponding inflammatory sequelae.

Laser and energy-based devices' complications in dermatology.

Laser dermatology is an ever-expanding part of the specialty used extensively for both aesthetic and medical conditions. Advances in laser technology have led to an expansion in the number of devices available, with as a consequence an increase in the total number of complications. Fortunately, the current technology has improved greatly which adds to the safety profile of such devices; nevertheless, thorough knowledge of laser complications and how to avoid them is paramount for any practitioner who uses such technology.

Superficial Epidermolytic Ichthyosis-Hypertrichosis as a Clue to Diagnosis.

Superficial epidermolytic ichthyosis (SEI) is an autosomal dominant disorder caused by a mutation in the keratin 2 gene and clinically characterized by mild hyperkeratosis, superficial blisters and shedding, referred to as the moulting phenomenon. We report a case of SEI in an 18-month-old girl presenting with marked hypertrichosis. Although not invariably present, we believe that hypertrichosis can be an important clue for diagnosis.

Acquired localised hypertrichosis in a Chinese child after cast immobilisation.

Hypertrichosis refers to excessive hair growth that is independent of any androgen effect. Hypertrichosis could be congenital or acquired, localised or generalised. The phenomenon of acquired localised hypertrichosis following cast application for a fracture is well known to orthopaedic surgeons, but is rarely encountered by primary care physicians. We describe a 28-month-old Chinese boy who had fracture of right leg as a result of an injury. He had a cast applied by an orthopaedic surgeon as treatment. On removal of the cast 6 weeks later, he was noticed to have significant hair growth on his right leg compared with the left leg. The patient was reassessed 3 months after removal of the cast. The hypertrichosis resolved completely with time. This patient was one of the youngest among the reported cases of acquired localised hypertrichosis after cast application. We illustrate the significance of management of post-cast-acquired localised hypertrichosis in the primary care setting.

POEMS Syndrome: A Rare Disease With A Challenging Diagnosis.

A complex conglomerate of symptoms, signs, and abnormalities are present with POEMS syndrome, making the diagnosis, management and follow-up a challenge. Recognizing the disease early on may be difficult. Many patients are initially misdiagnosed as having others disorders, for example: multiple myeloma. There is no standard treatment for patients diagnosed with POEMS syndrome.